This paper deals with replication of Bombyx mori nuclear polyhedrosis virus in a continuous cell culture of Bombyx mori. BmNPV—Bm cell system was established Light microscopy and electron microscopy studies demonstrated that infected cells appeared to typical cytopathologcal change. Cells over 95% were infected Ulerastructural observation and morphogenetic characteristic of BmNPV replication in BmN cell line were described, specially the Loop-shaped structure in ce...