Property expropriation is an act which can deprive the property rights of obligee on the basis of the purpose of public interests and offer the fair compensation beforehand according to the condition and process of laws.

In this article,the author fully introduces the common fair market evaluation approaches,time of evaluation,fee interests,less than fee interests and components of property affecting fair market evaluation of just compensation during the process of condemnation in America.

Almost every democratic constitutional country formulates the principle of just compensation.

There is theoretical and practical significance in the just compensation for the expropriation of land and properties.

Taking Yellow River Irrigation District of People s Victory Canal as an experiment plot,the paper dealt with the countermeasures of reasonable compensation to agricultural cost water price.