An azo compound with the following general formula (I): ##STR1## wherein X is selected from the group consisting of hydrogen atom, lower alkyl group, lower alkoxy group, halogen atom and cyano group;Y is phenylene or naphthylene group;Z.sub.1 and Z.sub.2 are independently the divalent group represented by the following formula: ##STR2## wherein A is a divalent group derived from the aromatic hydrocarbon or heterocyclic compound including one or more nitrogen atoms in the ring; andn is 1 or 2,is disclosed. Such compounds are useful in forming a photosensitive layer of an electrophotographic photoreceptor.