Bombyx mori is one of the most genetically studied and economically important insects around the world, with many different geographic strains: Japanese, Chinese, European and Indian. In Brazil, the sericulture is the main activity for small farmers. The commercial hybrids are a result of crosses between Japanese strains, more productive, and Chinese ones, more resistant to culture conditions. However, the B. mori can be infected by different pathogens, such as the silkworm nuclear polyhedrosis virus (BmNPV), that causes great economical losses. The breeding and commercialization of silkworm with high resistance to diseases are very important to the silk industry. In Paraná, state that produces by itself 90% of green cocoon in Brazil, a new geographic BmNPV strain with multicapsid characteristic named BmMNPV was recently isolated. The Random Amplified Polymorphic DNA technique (RAPD) has been successfully applied to identify genetic markers linked to resistance and susceptibility to diseases. The aim of this study was to characterize strains resistant to BmMNPV through molecular marks. In this way, sixteen strains on 5^o instar were infected with 1.44x10^-6 OBs/ml of BmMNPV. Silkworm DNA from the most resistant strain and from the most susceptible strain was extracted and analyzed by RAPD approach using the primers OPA-18₇₀₀ e OPY-11₄₀₀ described as to be linked, respectively, to BmNPV resistance and susceptibility. Three days pos inoculation, the larvae shown initial infection symptoms and after 4 days they start to die. Amongst the analyzed strains, the Chinese M11-A had 94% of mortality (46% in larval and 48% in pupae stage) showing to be the most susceptible to BmMNPV, and the Japanese strain C24-A, which had a mortality of 22% (8% in larval and 14% in pupae stage), the most resistant. The genomic DNA analysis of the M11-A and C24-A with the OPY-11₄₀₀ showed that the expected band of 400 bp was present only in M11-A which validates the susceptibility of this strain to BmMNPV. When the OPA-18₇₀₀ was utilized, the expected band of 700 bp was present only in the C24-A, the most resistant strain to BmMNPV in the inoculation experiments. These results showed that this molecular analysis is accurate to characterize BmMNPV resistant B. mori strains and help to select the best parental silkworm for breeding programs.