The best remedy that can provide the necessary stability of the constitutional provisions, it is considered a more complex procedure of amending the constitution, compared with the usual law. The convening of a constituent assembly to amend the text of the current constitution is usually not necessary, but in some countries, such as Bulgaria, to change the "fortified" articles of the constitution is necessary.

Amendments made by the decision of the parliament or on the basis of the results of the referendum, but such decisions are linked to specific requirements. First of all, the very proposal for the amendment requires compliance with certain conditions. If the project is an ordinary law in some countries may make a member of Parliament, the draft Constitution has been amended to change only the head of state, the government, certain group members (in Turkey - one third of the parliament), the subjects of the federation (in Brazil - half of the states) and etc.

However, in an amendment to the U.S. Constitution can make, and one deputy, and for 200 years it was suggested more than 10 thousand, but made only 27. The amendments to the constitutions of the states in the United States may be amended in the manner and the people's initiative - a group of voters in different states from 3 to 20% of the voters who participated in the last election for governor of the state.

As a rule, the amendment must be adopted not easy, but a qualified majority in each House of Parliament (two thirds of the total votes in Austria, Italy, the Netherlands, etc., 3/5 - in Greece, Spain) or (less often) in a joint session of the chambers (3/5 votes in France). Such a decision is not always final. Often it is necessary that it be adopted by Parliament twice a specific interval (in Greece - at least a month in Italy - 3 months). In some countries, a second vote must take place only after the election of a new Parliament (Belgium, Finland).

After Parliament passed an amendment to the constitution, in some federations, its decision must be approved by a specified majority of subjects of the federation (in the U.S. - 3/4). In Denmark, Switzerland and some other countries it is approved by referendum. In France, these three fifths vote of Congress (joint session of Chambers) - is also a statement-making chambers. Certain articles of the Constitution are changed by a qualified majority, the other - a simple majority (eg, India).

In most cases, the constitutional amendments are not subject to presidential veto (his request to consider the law a second time) and should be published, but in some countries the president's veto applies to laws on amendments (India, Netherlands, Pakistan), although not used in practice.

Almost always in the new constitution included provisions prohibiting revise certain provisions (in some countries - a republican form of government in Portugal - the right of the democratic opposition in Germany - the principles of legal, democratic and federal state in Mauritania - the principles of multi-party system). some countries (Greece, Romania) unchanged declared entire sections of the constitution. Often prohibited to change the constitution in times of emergency (eg Spain), sometimes - for a certain period after its adoption (in Brazil, Greece, Portugal - 5 years).

When military coups often used emergency order changes and cancellations of the constitution: the military advice cancel or suspend some of its chapters or articles, and sometimes the entire text. As a rule, later suspended the constitution does not resume, military transition to civilian rule is developing