Objective To investigate the correlation between the combined detection of homocysteine（Hcy） and cystain-C（Cyc-C）with gestational nephrotic syndrome. Methods The serum levels of Hcy and Cyc-C in 23 cases of gestational diabetes with nephropathy, 58 cases of gestational diabetes without nephropathy group and 50 cases of health controls were detected. Results There were significantly difference on Cys-C levels between gestational diabetics with nephropathy group, without nephropathy group and normal control (P<0.05). There were significantly difference on Hcy levels between gestational diabetics with nephropathy group and without nephropathy group (P<0.05), between gestational diabetics with nephropathy group and health control group (P<0.05). Conclusion The combined detection of serum levels of Hcy and Cys-C could play an important role in the assessment of the severity of diabetic nephropathy.