This paper presents a new method for the detection of isomorphism in kinematic chains which plays an important role in structural synthesis of kinematic chains. The proposed method uses the new invariants called as connection string & connection value . These invariants are based on the degree of links and used as an identifier of a kinematic chain (KC). The proposed method is easy to compute, reliable and capable of detecting isomorphism in all types of KC, i.e. chains of single or multi degree of freedom with simple joints. This study will help the designer to select the best KC and mechanisms to perform the specified task at conceptual stage of design.