Abstract: Inheritance is one of the most important features of object oriented programming technology. Based on the analysis of the traditional inheritance mechanism, a new inheritance mechanism——soft inheritance is proposed, which enhances the traditional inheritance by providing analogy definition, analogy analysis and analogy derivation in object oriented programming. The new mechanism supports both the traditional sub class relationship and the new analogy relationship and consequently makes software reuse more flexible and effective. Meanwhile, a new self designed object oriented language ND Polya supporting soft inheritance is discussed and its supporting system is introduced.