Objective:To investigate the expression of cyclinD1,P16 and cyclinA1 in the fibroblasts of keloids and hypertrophic scars,and explore the relationship between the genesis of two different kinds of scars. Methods:Normal skin tissues were used as control group,and the expression of cyclinD1,p16 and cyclinA1 were screened in hypertrophic scars and keloids by immunohistochemical SP method. Results:In keloids,positive expression rate of cyclinD1 is 91.7%, that obviously higher than 45.5% in the hypertrophic scar group as well as the control group(P < 0.05);81.8% as the positive rate of p16 in hypertrophic scar group is significant higher than the rate of keloid group,which is 33.3% as well as the control group(P < 0.05);the rate of cyclinA1 in keloids (75.0%) is higher than hypertrophic scar group (27.3%) as well as the control group(P < 0.05);cyclinD1 and cyclinA1 in hypertrophic scars, as well as the expression rate of P16 in the keloid group,are higher than that in the normal skin group,but the difference are not significant. Conclusion:In the progress of scar formation,the imbalance expressions of cyclinD1 and p16,as one pair of the positive and negative cell cycle regulatory factors and positive regulatory factor of cyclinA1,play important roles of the prognosis of scars.