Objective To investigate the effects of different static compressive stress on the biological characteristics of the mandibular condylar chondrocyt(es MCC). Methods The static compressive stress with a magnitude of 12, 24, 36 kPa were exerted on the third passage of MCC for one hour. The MCC was dyed by immunohisto- chemical method. The changes of the expression of collagen type Ⅰ , Ⅱ , Ⅲ and proteoglycan ( PG) were evaluated by a pathologic portraits analytic system. Results The static compressive stress with a magnitude from 12 to 24 kPa can enforce the expression of collagen type Ⅰ, Ⅱ, Ⅲ and PG of MCC. However, the decrease of expression of collagen type Ⅰ and PG of MCC was detected when exerted by the static compressive stress with a magnitude from 24 kPa to 36 kPa. Conclusion The static stress of proper magnitude can make MCC more differentiate. However, the static stress of over- magnitude may make the biological characteristics of MCC weaken and express some characteristics of dedifferentiation.