Abstract: Legume seeds are rich and varied source of secondary plant metabolites which are toxic or anti metabolic towards insect pests, possibly by virtue of these toxic substances they show resistance and susceptibility against stored grain pest species. Despite the potential nutritional and health promoting value the presence of antinutritional factors limit biological value and usage of legumes as food. Antinutritional factors interfere with digestion and also make the seeds unpalatable when consumed in raw form. Based on these possibilities the biochemical basis of bruchid resistance has been studied in different legume genotypes and the results recorded revealed that highly resistant soybean genotypes possesed high amount of fats, proteins and antinutritional factors (phenols and 4-5 times more trypsin inhibitors) than cowpea and chickpea (kabuli>desi) genotypes which contain high amount of carbohydrates and low amount of antinutritional factors and were susceptible towards Callosobruchus species.