Objective To investigate the apoptosis of articular chondrocyte and the expression of Bcl-2, Bax, Fas and iNos in articular cartilage with Kashin-Beck disease(KBD) in order to understand the pathogenesis of chondronecrosis in KBD. Methods The collected samples of human articular cartilage were divided into two groups: control group (15 samples from 15 cases), KBD group (15 samples from 15 cases). KBD patients were diagnosed by "Pathological Criteria to Diagnose KBD in China". Chondrocyte apoptosis was detected by TUNEL staining, and the Bcl-2, Bax, Fas and iNos positive articular chondrocytes were stained by the B-SA of immunohistochemistry. Articular cartilage was classified three zones and the positive rate were counted by light microscope for cytoplasimic staining by polyclonal antibodies of Bcl-2, Bax, Fas and iNos and apoptotic chondrocytes by TUNEL. Results ① The percentage of positive apoptotic chondrocytes stained by TUNEL in the middle zone of articular cartilage from the KBD-children group(33.60±2.71%) was higher than that of the control (1.33±0.41% t=11.59, g=28, P