This paper presents a new method to identify the distinct mechanisms (shortened as DM) from a given kinematic chain. The kinematic chains (shortened as KC) are represented in the form of the Weighted Physical Connectivity [WPCM] Matrix. Two structural invariants derived from the characteristic polynomials of the [WPCM] matrix of the KC are the sum of absolute characteristic polynomial coefficients (shortened as ∑ WPCM) and maximum absolute value of the characteristic polynomial coefficient (shortened as MWPCM). These invariants are used as the composite identification number of a KC and mechanisms. It is capable of detecting DM in all types of simple jointed planer KC with same or different kinematic pairs (shortened as KP). This study will help the designer to select the best KC and mechanisms to perform the specified task at the conceptual stage of design. The application of this study is in research and development industries. The proposed method has been explained with the help of examples and does not require any test for isomorphism separately.