Abstract: Study on dynamic expression of the apoptosis related protein Bax and Bcl-2 in immunity organs of Gushi chickens was performed and analyzed by using immunohistochemistry technology and Leica Microsystems. The results showed that the expressions of Bax protein in different immunity organs were observed, however, numbers of the positive cells of Bax protein were different on different developmental stages. The positive Bax-protein was found in cell membrane, cytoplasm and nucleus of lymphocytes. The positive cells were dispersedly (or in clusters) distributed in different places for different immunity organs. Most of the positive cells, in spleen, were found in periarterial lymphatic sheath, red pulp, edge of splenic nodules and marginal zone, few of them in inner of splenic nodules. The positive cells, in thymus, were localized mainly in the connective zone of thymic cortex and thymic medulla , secondly in thymic medulla, and a few in thymic cortex. In Bursa, the majority of positive cells were observed in lamina propria of mucous membrane and areas between lymphoid follicles, a few in edge of lymphoid follicles, and few in inner of lymphoid follicles. The expression of Bcl-2 in the immunity organs of Gushi chickens was similar to that of Bax, but the expression level of Bcl-2 was less than that of Bax. All results mentioned above indicated that the apoptosis related protein Bax and Bcl-2 participated in the regulation of apoptosis of thymocytes and lymphocytes, and played the important roles in keeping the immunity organs stable.