Objective To explore the effect of platelet-rich plasma(PRP) with different concentrations on proliferation of human skin fibroblasts and expression of collagen and hyaluronic acid(HA) in vitro.Methods Primary cultured human skin fibroblasts(HSFs) with different concentrations(1%、5%、10%、20%、30%、50%) of PRP culture medium were treated as experimental groups,and take serum-free medium as negative control group and culture medium containing 10% newborn calf serum as positive control group.MTT,RT-PCR and ELISA were respectively used to measure HSFs proliferation,collagen expression and hyaluronic acid expression at the 3rd,5th and 7th day.Results MTT assay indicates that the experimental groups can all promote the proliferation of HSFs compared with the negative control group(P<0.01),and the effect showed on increasing tendency.RT-PCR detection showed that the target genes Collagen Type 1(COL1) and Collagen Type 3(COL3) were all expressed in the 50% PRP group,negative control group and positive control group,but there were no significant differences among the three groups.ELISA showed the enhancement of HA expression compared with the negative control group(P<0.01).The HA expression was significantly increased with the PRP concentration of 30%-50%(P<0.01).Conclusion PRP could promote the proliferation of HSFs and the function of the synthesis of collagen and HA.