Primers were designed according to sequence of polyhedron envelope protein gene(pep) of BusuNPV, then the polymerase chain reaction(PCR) technology was used to detect Buzura suppressaria nucleopolyhedrovirus DNA sequences from viral polyhedral inclusion bodies(PIB), and the DNA sequences was detected from the egg and offspring.The level of sensitivity by the technology was as low as 1 fg·mL-1 DNA.Morphology and biological activity studies of BusuNPV showed that,the BusuNPV saved by laboratory was single-nucleocapsid nucleopolyhedrovirus (SNPV).An infectivity test of BusuNPV against the second instar larvae of Buzura suppressaria was carried out in out laboratory,and LC50 of BusuNPV was determined as 6.65×104 PIB·mL-1, and LT50 of BusuNPV was 5.69 d.