Abstract: In view of the relationship between man and flood,the definition of non-structure measures for flood prevention is given as that,the non-structure measure for flood prevention is the measure which achieves the aim of flood prevention and flood disaster reduced by restriction of actions of man-self and improvement of the relationship between man and flood but not by structures.According to the definition,the non-structure measures for flood prevention is classified as four classifications, they are in view of flood physics properties,flood risk conception,management science,laws and regulations respectively,and the tactical thinking of each kind of non-structure measure for flood prevention is expounded as well.