By meams of in vitro culture of pollinated pistils we overcame the sterility in the interspecific cross between Brassica pekinensis Rupr. and B. oleraceavar.capitata L. and obtained diploid and tetraploid offspring. And we made comprehensive studies about their morphology, kar-yograms, analysis of isoenzymes and the fertility in back cross. The morphology of F_1 hybrids was intermediate between their parents with a tendency to male parent. The diploid hybrids showed evident hybrid vigor, while the tetraploi...