Significant changes in the structure of the federation started with the Constitutional Amendments in 1967 and 1968, which gained the integral form in 1971. Amendments marked the beginning of the concrete implementation of stands of the 8th Congress of the SKJ held on December 7-13, 1964. On this occasion for the first time after World War II the national issue was publicly "opened," the issue of economic causes of national inequalities was raised, a connection between the bureaucratic centralism, "big state hegemony" and nationalism was established. What started, in fact, was the process of alteration of relations between the federal state and republics, resulting in a fundamental transformation of the federation. Yugoslavia was built as a "federation of balance." The monolithic social and political life was replaced by the "self-management federalism." Republican elites started thinking about Yugoslavia as a "transitional" creation. Administrative boundaries among republics (formerly described as "veins in marble") became the boundaries of autonomous states. The Yugoslav state was increasingly becoming a "federating" federation.
The amendments weakened and limited the autonomy of the federation and put it under the supervision of republican and provincial structures. Republics and autonomous provinces grew stronger. Republics, as the social and political communities, were treated as national states. The status of autonomous provinces was expanded and "sovereign rights" started to be implemented in provinces. A "two-tier federation" was created. The position and status of Serbia and autonomous provinces in the federation essentially became equal. Constitutional provisions defining socialist autonomous provinces as an integral part of SR Serbia were declarative because within Serbia the provinces enjoyed the status of "territorial and sovereign social and political autonomy."
The Constitutional alteration of the federation started through Amendments I-VI, which the Federal Council adopted on April 18, 1967, The Council of Nationalities was reintroduced as the general jurisdiction chamber at the Federal Assembly. Changes were made in the composition of SIV and position of the federal bodies of power.
Amendments VII-XIX, adopted on December 26, 1968, renamed the Autonomous Province of Kosovo and Metohija into the Socialist Autonomous Province of Kosovo. Provinces were granted the right to adopt their own constitutional laws.
Constitutional amendments more comprehensively defined the autonomous provinces as wider social and political communities within Serbia with autonomous rights and responsibilities. Autonomous provinces were granted the status of a constituent element of the federation, although they did not have the features of federal units like republics. Under the amendments, the provinces were to have their supreme courts and other judicial bodies. The territorial integrity of provinces was guaranteed and their boundaries could be altered only if their assemblies approved. The term national minorities was replaced by the term ethnic groups and their equality with the peoples of Yugoslavia was guaranteed.
The popular name for Amendments XX-XLII, adopted on June 30, 1971 was "workers' amendments" because they comprehensively defined the position of working people in the associated labour. Under these amendments, working people in the basic organisations of associated labour received the right to a function and to means of social reproduction. The functions of the federation were significantly reduced in the field of investments and legislation. The federation carried out certain functions in the joint interest of all peoples and ethnic groups of Yugoslavia, while some were carried out only on the basis of harmonised stand of republics and autonomous provinces.
Under the amendments, the Yugoslav federal state was defined as a "state union of voluntarily united peoples and their socialist republics as well as the socialist autonomous provinces of Vojvodina and Kosovo which are within the Socialist Republic of Serbia, based on the authority and self-management of the working class and all working people and the socialist self-management democratic union of working people and citizens and equal peoples and ethnic groups."
Changes were introduced in the institutions of the federation and in addition to the president of the republic the Presidency of the SFRY was established as the collective head of state and bearer of the legislative and political initiative. Josip Broz Tito was the president of the republic and president of the Presidency of the SFRY. The position and role of SIV and federal bodies of administration were changed considerably. The bodies of the federation were formed on the parity basis.
In addition to the Yugoslav People's Army, territorial defence was introduced as another armed force of the SFRY. This will have far-reaching consequences when the disintegration of Yugoslavia begins.
List of Constituent Acts of Yugoslavia | 
