Background: One of long-term complication of diabetes mellitus is diabetic nephropathy, which affect kidney and other organs. Suggestion and evaluation of its early diagnostic markers is a goal of many researches to help in providing highly efficient biomarkers. Objectives: This study aimed to assess cystatin c as early biomarker for diabetic nephropathy in Sudanese with type2 diabetes, in comparison with ACR Methodology: It is a Descriptive cross sectional study, conducted during the period from March to July 2015 in 72 patients with type2 diabetes mellitus, the serum cystatin c, serum creatinine and spot unrine for ACR tested. Then, the Generated data analyzed using the statistical package (SPSS). Result: Plasma cystatin c level higher in albuminuric than normal urine group. It is directly proportional to ACR and it is early raise than creatinine, also it positively correlate to duration of diabetes. Conclusion: Cystatin c has diagnostic efficiency similar to that of ACR in detecting albuminuria. Furthermore it can detect nephropathy earlier than ACR.