A mixture of bisamine compounds comprising a bisamine compound represented by Formula (1) and a bisamine compound represented by Formula (2): A-X-A Formula (1) A-X--B Formula (2) wherein, A and B represent a different substituted amino group represented by Formula (3), X represents a bivalent linkage group: ##STR00001## wherein, each of Ara and Arb independently represents an aryl group which may have a substituted group, and Arc represents an arylene group which may have a substituted group, and Ara, Arb and Arc may be combined to form a ring structure.