Objective To investigate the serum cystatin C(Cys C)levles in different age and sex health physical examination people,and to analyze the correlation between different ages,different genders and Cys C levles. Methods 648 healthy subjects checked with physical examination were selected.611 patients with normal renal function were selected.The serum Cys C and Cr concentrations were determined and statistically analyzed according to different age or gender groups.The serum Cys C and Cr concentrations of other 37 patients with abnormal renal func-tion were detected and compared with normal renal function people in the same ages.Results There were no signifi-cant differences in serum CysC levels between men and women in different ages and normal renal function people(t =2.449,P =0.092;t =0.176,P =0.872;t =2.030,P =0.135;t =2.376,P =0.098;t =1.549,P =0.219;t =1.732,P =0.182;t =1.095,P =0.353;t =1.732,P =0.182;t =2.449,P =0.092;t =2.611;P =0.080).There were significant differences in serum Cys C level between men,women and combined with normal renal function(F =5.662,5.615,7.253,all P <0.05).Taken the linear correlation analysis by age with serum Cys C level among men, women and combined with normal renal function groups,the results showed that had positive correlation(r =0.525, 0.511,0.522,all P <0.05 ).Renal function of different genders in the health physical examination people over 50 years of age appeared serum Cys C positive persons,and the positive rate of each gender group increased alone with the increase of age(F =7.324,7.341,7.452,all P <0.05).The Cys C,Cr content and positive rate of renal function in health physical examination people were significantly lower than abnormal renal function people (t =31.080, 15.472;χ2 =17.043,34.105;all P <0.05).Conclusion There is an evident positive correlation in health physical examination people between serum Cys C level and the ages,and are increased alone with increase of age,which is increasing evidently alone with increase of age,while has no correlation with gender.