By using a concept of interrelation quadruplet between line segments, a new method for recognition of object families is introduced. The interrelation quadruplet, which is invariant under similarity transform of a pair of line segments, is used as a feature information for polygonal shape recognition. Several useful propertes of the interrelation quadruplet are derived in relation to efficient recognition of object families. Compared with the previous methods, the proposed method requires only small space of storage and is shown to be computationally simple and efficient.