Objective  To explore the correlation between the four kinds of serum target, CysC, RBP, Hcy and CRP and stage of diabetic nephropathy. Methods  The 468 diabetic nephropathy patients were selected for this study from people's hospital of Fuyang during July 2016 to August 2018. The GFR was calculated using simplified formula of MDRD and the patients were grouped five groups(stage I to stage V) according to K/DOQI, the treatment guidelines of chronic kidney. Meanwhile the level of four routine serum targets, CysC, RBP, Hcy and CRP,were detected by automatic biochemical apparatus of Siemens 2400 model. And the datum were analyzed using the software of Graphpad 50 retrospectively. Results  The level of serum creatinine 468 diabetic nephropathy patients was detected to evaluate the extent of renal injury. There were the five groups containing 233, 70, 95, 37 and 33 patients from stage I to stage V respectively. And then the correlation between targets and renal injury was significant, the statistics results showed the correlation coefficient(r²) was 0.5264 between renal injury and CysC（P<0.001）.The correlation coefficient of RBP, Hcy (r²) was 0.3355 and 0.2877（P<0.001） respectively. The CRP showed a low correlation with renal injury(r²=0.0122,P=0.0168). Conclusions  This study suggested the level of four serum targets is valueable for evaluation of renal injury and CysC maybe evaluate the degree of renal injury.