A stilbene derivative compound having a specific substituent at the specific position thereof to exert good compatibility with a binder resin and to tend to be uniformly dispersed in a photoconductive layer so as to allow prolonged specified sensitive property, a process for the production thereof, and an electrophotographic photoconductor containing the stilbene derivative compound are provided.For preparing a stilbene derivative compound represented by the general formula (1), a specified formylated triphenylamine derivative compound and a specified diphosphate ester derivative compound are allowed to be reacted with each other in the presence of a catalyst. ##STR00001## (wherein "A" is a divalent organic group having aromatic hydrocarbon as a basic skeleton, each of the plural R.sup.1 to R.sup.7 is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or the like, each of the plural Ar.sup.1 and Ar.sup.2 is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, each of repeating numbers a and b is an integer of 0 to 4, and c is an integer of 1 to 3.)