The 24th plenum of the Party's Central Committee of the third congress (September 1975) decided to complete the national unification and take the whole country toward socialism quickly, vigorously and steadfastly.

The general election for the National Assembly of the whole country (the 6^th National Assembly) was held on April 25, 1976 with 23 million voters (accounting for 98.8 percent of the national total) having gone to the poll. From June 24 to July 3, 1976, the National Assembly of the unified Vietnam held its first session in Hanoi to elect top leaders of the State and decide to rename the country the Socialist Republic of Vietnam with Hanoi as its capital city, and rename Sai Gon-Gia Dinh area Ho Chi Minh City.

From December 14-20, 1976, the fourth national congress of the Party was held in Hanoi capital with the participation of 1,008 delegates representing more than 1,550,000 Party members. The congress was also attended by 29 foreign delegations. The congress summed up and assessed the significance of the victory and the experiences drawn from the anti- US war of resistance for national salvation. The congress set forth the general line for the socialist revolution and the line for building the socialist economy in Vietnam, directing towards the objectives of building a new regime, a new economy, a new culture and the new socialist men. The congress elected the 4^th Central Committee comprising 101 full-fledged members and 32 alternate members. The Central Committee elected the Political Bureau comprising 14 full-fledged members and 3 alternate members. Comrade Le Duan was elected the General Secretary of the Party's Central Committee. The congress also decided to change the name of the Vietnam Workers' Party into the Communist Party of Vietnam.

In materialization of the lines charted out by the fourth Party congress, the whole country ebulliently carried out the five-year (1976-1980) plan for economic rehabilitation and development. In the South, the transformation of various economic sectors was effected, establishing the absolute superiority of the socialist economic sector in the State-run and collective forms. In the North, the task of consol the socialist relations of production was accelerated. On September 20, 1977, Vietnam became 149th member of the United Nations Organization. Following the liberation of the South, the Vietnamese people had to fight the war of aggression staged by the Pol Pot (Cambodia) clique in the Southwestern border region, firmly defending the Fatherland and saved the Cambodian people from genocide (1975-1979), and later won the victory in the war for the defense of national independence and sovereignty in the Northern border region from February 17 to March 18, 1979. With heavy war consequences, with newly arising difficulties and trials, particularly the very heavy task of defending the Fatherland, and together with the subjective mistakes and shortcomings in the socialist transformation and slow change in the managerial mechanism, the country was pushed into a socio-economic crisis during the late '70s. Only 13.4 tons of food a year were harvested against the target of 21 million tons set by the fourth Party congress for the 1976-1980 period. The annual economic growth rate was recorded at only 0.4 percent on average.

To surmount difficulties and trials, the Communist Party of Vietnam straight- forwardly evaluated the situation and found the remedial Solutions. The sixth plenum {September of the Party's Central Committee of the fourth congress decided to "amend and improve the existing policies, particularly the policies on circulation and distribution, aiming to give a boom to production". can be considered the policy initiating the process of searching for ways to renewal in Vietnam.

On December 18, 1980, the 6^th National Assembly, at its 7th session, passed the new Constitution. The 1980 Constitution institutionalized the lines of the Communist Party of Vietnam in the period of transition to socialism.

The Party and the Government attached importance to studying the theories and sciences on socio-economic management while summing up experiences drawn from realities in localities and grassroots establishments in order to work out proper policies. On January 13, 1981, the Secretariat of the f Central Committee issued Directive 100-CT/TW on improving the work of labour package assignment expanding the assignment of product package to each labour group and each labourer in the agricultural cooperatives. On January 21, 1981, the Government issued Decision No.25/CP on elaboration a three-phase plan, initially giving prominence to raising the spirit of sovereignty and dynamism managers and labourers in the State-run economic units. These were important steps in renewing the managerial mechanism and the process of partial renewals in a synchronous and comprehensive manner.

From March 27-31, 1982, the fifth national congress of the Communist party of Vietnam was held in Hanoi with the participation of 1,033 delegates representing 1,727,000 members of 35,146 grassroots Party organisations, and 47 foreign delegations. The congress elected the 5^th Central Committee with 116 full-fledged members and 36 alternate members, which elected the Political Bureau comprising 13 full-fledged members and two alternate members. Comrade le Duan was re-elected the General Secretary. The fifth Party congress decided to continue renewing the mechanism of economic management, acknowledging the de-facto existence of many economic sectors, adjusting the steps and scale of the socialist industrialization process and considering agriculture the first and foremost front. The congress also affirmed that our country was being in the first stage of the period of transition toward socialism.

Following the 5^th party congress, various economic branches, localities and production as well as business establishments ebulliently renewed their management mechanisms and searched for new ways to bring about economic efficiency and raise the living standards of the labourers. The sixth plenum (July 1984) of the Party's 5^th Central Committee discussed the urgent tasks in improving the economic management; particularly the 8th plenum of the Party's 5^th Central Committee in June 1985 held that "only by abolishing the mechanism of bureaucratic centralism with State subsidies and properly implementing the regime of democratic centralism as well as the socialist economic and business cost-accounting can production and business be stepped up with efficiency". The plenum considered the abolition of bureaucratic centralism with State subsidies in prices and salaries the first important step of decisive significance for the total shift to socialist business cost accounting.

The 10th plenum (June 1986) of the Party's 5^th Central Committee reviewed the situation after the price- wage-money adjustment (September 1985) and confirmed the official renewal of management mechanism, abolishing the mechanism of bureaucratic centralism with State subsidies. On July 10, 1986, comrade Le Duan passed away. On July 14, 1986, the Party's Central Committee met and elected comrade Truong Chinh the General Secretary. The 11^th plenum (November 1986) of the Party's Central Committee completed the drafting of the documents to be presented at the 6th national congress of the Party.

In a gradual renewal approach under the correct guidelines and policies of the Party and the State, the innovations, dynamism and creativeness of the people in all localities as well as production and business establishments, the Vietnamese economy during the years of 1981-1985 witnessed good steps of development. The average annual food output reached 17 million tons; the average industrial output rose 9.5%/year. The average annual national income was up by 6.4 percent. The technical and material bases of socialism were built considerably with hundreds of automation works and thousands of medium- or small-sized works, including important establishments for power generation and supply, petroleum, cement, engineering, textile, communications. The production capacity was raised with the increase of 456,000 kW of electricity, 2.5 million tons of coal, 2.4 tons of cement, 33,000 tons of yarn, 58,000 tons of paper, 309,000 ha of fields being irrigated and 186,000 ha relieved from water-logging. The national independence, sovereignty and security were firmly maintained. However, the socio-economic situation and people's life were still confronted with numerous difficulties, the socio-economic crisis remained serious. Such a situation demanded the Communist Party of Vietnam decided to go ahead with comprehensive and absolute renewal along the lines charted by the 6th national congress of the Party (December 1986).