The Ninth-of-May (1948) Constitution was the second constitution of Czechoslovakia, in force from 1948 to 1960. It came into force on 9 May, shortly after the communist seizure of power in the country on 25 February 1948. It replaced the 1920 Constitution. Work on the new document had been underway since the summer of 1946. As a result, it was not a fully Communist constitution, and was superficially similar to the 1920 Constitution; indeed, many elements were directly carried over from the earlier document. However, it was close enough to the Soviet model that President Edvard Beneš refused to sign it and resigned. It was flagrantly violated by the Communist Party of Czechoslovakia (KSČ), the government and many individuals throughout the period of its being in force, especially regarding the provisions on private ownership and human rights.
Since the country's liberation, there had been many disputes concerning nationalization, the relation of Czechs and Slovaks and other crucial issues. After the Communist take-over in February 1948, the Communist concept was largely applied. Although the constitution did not organize government administration under the Leninist principle of democratic centralism (a provision only incorporated in the following "socialist" 1960 Constitution of Czechoslovakia), it did declare Czechoslovakia a "people's democracy" and dictatorship of the proletariat under the leadership of the KSČ, as was the case with other Communist parties in the Soviet bloc.
The constitution declared that the economy of Czechoslovakia was based on nationalized industries, nationalized trade and a nationalized financial sector. The government sector was declared the basis of the economy, but it protected the private sector and cooperatives as well. It also granted a small degree of autonomy to Slovakia, which was given its own legislative body and governmental structure, although these were made subordinate to the central authorities in Prague. The parliament continued to be called the National Assembly.