Morphological charaters of broodstocks and their glochidia were compared in reciprocal hrybid of triangle mussel Hyriopsis cumingii from two drainage systems.The results indicated that the umbo position of broodstock from Taihu Lake was significantly closer to anterior of shell,and the ratios of shell width and shell height to corresponding shell length were also obviously lower than those from Hongzehu Lake(P<0.01).The external feature of triangle mussel from Taihu Lake and Hongzehu Lake was long-flat type,round-plump type respectively.Glochidia Index of cross group H0T was(0.066 7±0.005 9),significantly higher than three other groups(P<0.01),and had observed heterosis(2.54%).The ratio of shell length to shell height of glochidia in Group T0H and T0T was(0.828 4±0.029 4),obviously lower than Group H0H and H0T which had(0.848 2±0.034 5)on average.T-test showed there was no significant difference between those groups which had the same source of female parents(P=0.286,P=0.106).These results indicated that this character was maternal inheritance,which was in accord with previous studies on intraspecific hybridization of mussel.More analysis will be concentrated on glochidia survival and growth of juvenile mussel in reciprocal hybird of this species.