Objective To study the association between the insertion(I)/deletion(D) polymorphism of the angiotensin-converting enzyme gene intron 16 (ACE/ID) and diabetic nephropathy (DN) among Chinese population by Meta-analysis. Methods Odds ratios of ACE/ID genotype distributions were analyzed in NIDDM or IDDM patients with and without DN. All the related studies on ACE/ID polymorphism and DN were identified while poor-qualified studies were excluded, and the risk of publication bias was estiMetad. The Meta-analysis software, RevMan 3.1, was applied for investigating heterogeneity among individual studies and summarizing effects across studies by proper statistical methods. Result The pooled odds ratios (with 95%CI) of DD vs ID + II and II vs ID + DD were 2.17 (1.74-2.70) and 0.49 (0.36-0.66) in NIDDM (12 studies), 3.92 (2.05-7.47) and 0.19 (0.09-0.43) in IDDM (3 studies) respectively (Plt;0.01). Conclusion In both NIDDM and IDDM, ACE/ID polymorphism is believed to be associated with diabetic nephropathy. The number of DN patients with DD genotype has been increased while that with II genotype decreased.