Abstract: This report proposes an intelligent biological genetic pattern,simulates the breeding process,provides a plan of biological parents' selection by the method of ex-pert system.Such a system includes knowledge representations of genetic law andexperts' experience of breeding and inference network about generating crossbree-ding descendants.This report discribes the organization of the ststem and method ofknowledge representation,by taking silkworm crossbreeding as example.But It is alsosuitable to other animales and crops.