Common antigens and analyzed the hemocytes of the lady crab (Charybdis japonica) were studied. Chinese mitten crab (Eriocheir sinensis), Dungeness crab (Cancer magister), and red king crab (Paralithodes camtschaticus) using a laser scanning confocal microscope (LSCM), flow cytometry (FCM), Western blotting (WB), and transmission electron microscopy. In this paper analyzed hemocyte classification and immunological characteristics of the whole proteins in these species and their antisera. Four antisera positively cross-reacted, to varying degrees, with hemocytes of the four species. Two subpopulations were classified in C. japonica, P. camtschaticus, and E. sinensis and three in C. magister. The LSCM results showed that four antisera were positive with the hemocytes of the four crustacean species, respectively. Dot fluorescent signals on the hemocyte membranes show a cricoid intensive distribution. FCM analysis showed a positive rate of cross-reaction, in which the reaction of the antisera with its own hemocytes was higher than that with other species' hemocytes. The positive rate of granulocytes was always higher than that of hyalinocytes. Western blotting results showed that the four antisera mainly recognized antigens with molecular weights of about 75 or 80 kDa in the hemocytes of C. japonica, 80 or 90 kDa in the hemocytes of P. camtschaticus, 30 and 82 kDa in the hemocytes of E. sinensis, and 43 or 70 kDa in the hemocytes of C. magister. More lanes reacted between hemocytes of E. sinensis and C. magister and their antisera. The results indicate antigenic similarities among the hemocytes of the four crustacean species.