Objective To investigate the relationship between the expressions of P16 and proliferating cell nuclear antigen(PCNA) in osteosarcoma and clinicopathological features,and explore the effects of them in occurrence and development of osteosarcoma.Methods The expressions of P16 and PCNA were detected by immunohistochemistry(SP) in 71 osteosarcima tissues and 10 normal bone tissues.Results ①The positive rate of P16 expression in osteosarcoma tissues was lower than that in normal bone tissues(P0.05).The expression of PCNA had positive relationship with osteosarcoma's prognosis(P0.05).③There was negative correlation between P16 and PCNA expressions(rs=-0.58,P