The chromosomes of three species ofCallosobruchus(Bruchidae: Coleoptera) have been studied in the male germ cells and nervous tissue of both the sexes. The karyotype is in confirmation with the basic type advocated for Coleoptera i.e. 9AA-XyDmale and 9AA-XX female. X and Y chromosomes form a typical parachute during first meiotic division. The Y-chromosome is, however, the smallest. Intraspecific variations in the chromosome number, by the loss of Y-chromosome, have been noted inCallosobruchus maculatusF. andC. chinensisL.