The initial linkage map of mungbean was developed from RFLP markers based on clones from mungbean, cowpea (V. unguiculata), soybean (Glycine max),and commonbean(Phaseolus vulgaris), and an interspecific hybrid population generated from a cross between V. radiata ssp. radiata and V. radiata ssp. sublobata. The map consists of 171 markers covering a total of 1,570 cM on 11 linkage groups, with an average interval of 9 cM between loci,as well asseveral important traits such as seed size, resistance to powdery mildew, and resistance to seed bruchids (Menancio-Hautea et al., 1992). The genetic relationships between mungbean and cowpea were also investigated by establishing the linkage arrangement of RFLPs.