Abstract: Study on the change of serum Cystatin C in the post kidney transplanted patients Xie lili, Liu juan, Gao qiang, Sun ping. Tianjin NO.1 centre hospital(300192) Abstract: Object To investigate diagnostic value of serum Cystatin C（Cys C） in the post kidney transplanted patients by dynamic monitoring the change and relationship among Cys C, sCr, BUN and Glomerular filtration rate (GFR). Method The serum Cys C, sCr and BUN were continuing measured in 29 patients during one day before operation and 1,3,5,7 day after operation compared with 20 controls. Particle-enhance turbidmetric immunoassay(PENIA) was used to detect the Cys C; sCr and BUN was measured by routine biochemistry assay; GFR was measured at by double plasma method. Result The value of the Cys C、sCr、BUN in the transplant group were higher than that in the control before operation, and all of them decreased at 1 day after kidney transplant operation, 47.6%, 37.4% ,33.0% respective, the level of GFR was negative correlated with Cys C(r=-0.892 P＜0.01), sCr(r=-0.811 P＜0.01) and BUN (r=-0.772 P＜0.01) .Conclusion The serum Cys C is a rapid, sensitive mark that could judge the kidney function after transplant operation. Key words: Cystatin C kidney transplant Creatinine BUN　Glomerular filtration rate