Abstract: Nineteen accessions of the wild plants including rice bean viz., Vigna umbellata Thunb. (Ohwi and Ohashi), a wild relative of the genus Vigna and other species belonging to Vigna were screened for their relative resistance to the bruchid, Callosobruchus maculatus F., a serious pest of stored pulses. The results showed that, accessions of V. umbellata were found to arrest the growth and development of C. maculatus, at grub stages in varying levels. Morphological characters like seed coat thickness and seed hardness were not found to be responsible for offering resistance to C. maculatus. The death of the grubs at the cotyledons was mainly due to the anti-nutritional factors in the cotyledons. Among the various biochemicals analysed, the trypsin inhibitors in the resistant accessions were in the order of 3-5 times higher (1576.12 to 3120.08 TIU g-1) than in the susceptible check (682.09 TIU g-1). Similarly the cysteine protease inhibitors were 7 times higher in the resistant accessions (2061.78 to 4923.62 CPIU g-1) compared to the susceptible CO 6 (686.77 CPIU g-1). The protein profile also showed the presence of low molecular weight proteins in the range of 14-29 kDa in the resistant accessions. The correlation between different anti-nutritional factors with that of index of suitability also showed a negative relationship. The role of these antinutritionals in relation to the C. maculatus infestation is discussed.