The principle of change of circumstances is the important principle of debt law that make the honest&credit principle as the starting point.

Once China began to work out a uniform contract law in the 90s of last century, the principle of change of circumstances was drawn some attention.

China is drafting its own civil code, which is the opportunity of building up the rules of rebus sic stantibus after the issuing of Contract Law.

Rebus sic stantibus system developed from case to statute law has become the current of world civil lawmaking .

If rebus sic stantibus principle is provided for in the law of the land contract in rural areas,it will play a crucial role in solving these dissensions,promoting agricultural development and maintaining rural stability.

So far, Majority people think that the seventy ninth article of the United Nations Convention on Contracts of the International Sale of Goods is the origin of Clausula Rebus sic Stantibus in international trade law.

The principle of changed circumstances is one of the important principles dealing with contract problems in many countries.

As one of the important principles for the performance of contract, changed circumstances is accepted by both continental law system countries and Anglo-American law system countries for its emphasis on the substantial justice.

Principle of changed circumstances is one of the most critical principle of contract law in civil law countries.

The corresponding theory in Chinese Contract Law is the principle of change of circumstances.