OBJECTIVE To demonstrate the phenotypic changes of mandibular condylar cartilage(MCC) cells during subculture in vitro. METHODS MCC cells were harvested from human fetus by digestion of collagenase and cultured in DMEM supplemented with 10% newborn calf serum, then they were passaged when reached confluence. Morphological changes were observed under phase-contrast microscope. Type II collagen, proteoglycan synthesis and type I, II and III procollagen mRNA levels were also studied in serial monolayer cultures. RESULTS During subculture, type II collagen and proteoglycan synthesis were decreased, being accompanied by a lower type II collagen mRNA level. In contrast, type I and III procollagen mRNA levels were elevated progressively. The morphology of polygonal-shaped chondrocytes was lost to the bipolar fibroblastic cells. CONCLUSIONS Passage and culture can affect the phenotypic property of MCC cells.