This paper reported the isolation, morphological character of Homoma magnamma granulosis virus (Hm GV) , and its tissue pathological changes and identification. This virus infringes fat bodies, blood cell and skin of the larva forming granulosis bodies in the cell cytoplasm, and its infectivity was found very high. The concentration of HmGV for 3th instar Humona magnamma larvae to determine the LC50 is 3. 42 × 10-5 mg·mL-1. According to the international classification system, it belongs to Bacuovirus subgroup B. It is one of the species of granulosis virus (GV).