With regard to the situation of large difference in space-time distribution of water resources and reduction in irrigation area in Fujian Province,the following aspects of large and medium-size irrigation districts in Fujian Province were studied: methods and rules for water right definition,types,price and realization modes as well as principles for water right trade.

It indicated that attending responsibility system was a reform based on the definition on right or a reform of property right which dealt with the problems of inspiring or preparing product elements.

Starting form the basic concepts and connotations of the property right theory including the property right,definition of property right,transaction,and transaction cost,etc.

Sometimes merely defining the property right is not enough,but must match the method and the measure of urging property rights to be exercised effectively,otherwise definition of property right cannot realize the efficiency goal automatically.

As to the vague definition of property right and the unfair compensation system in the legislation,the paper presents the policy suggestions for farmer specialized cooperative with the clearly defined individual property right mechanism and public funds property right,etc.

Then,through analyzing the externality and the property definition of different knowledge,it is pointed out that as exhaustively complete property definition of the knowledge is difficult,to eliminate the externality of the knowledge is not easy.