A new concept of link-path code has been ntroduced for a link of a planar kinematic chain
with simple joints. An algorithm has been developed for determining link-path codes for all the links of a kinematic chain, leading to the identification of its distinct mechanisms. Based on the concept of link-path code, an algorithm has also been proposed to quantify the degree of structural similarity between any two simple jointed planar kinematic chains with a given number of links and degree-of-freedom, as
well as between any two mechanisms of a planar kinematic chain with simple joints.