Objective: To investigate the levels of plasma CD146 and P-selectin in patients with type 2 diabetic nephropathy at different stages. Methods: A total of 80 patients with type 2 diabetes mellitus were enrolled in the present study. According to 24 h urinary albumin excretion ratio and renal function, they were further divided into group of diabetes without microalbuminuria (DN0, n = 20), microalbuminuria group (DN1, n = 20), macroalbuminuria group (DN2, n = 20) and renal insufficiency group (DN3, n = 20). Another 20 healthy subjects were enrolled as control group (non-DM). Plasma CD146 and P-selectin were measured by ELISA. Results: Plasma CD146 and P-selectin were significantly increased in patients with type 2 diabetes with microalbuminuria (DN1) compared with health control (CD146: 415.3 ± 29.0 vs. 243.5 ± 14.7 ng/ml, P < 0.05; P-selectin: 66.8 ± 3.4 vs. 45.3 ± 2.7 ng/ml, P < 0.001). With the development of diabetic nephropathy, both plasma CD146 and P-selectin level progressively rise, with the highest levels in patients with significant renal insufficiency (DN3: 515.9 ± 36.9 and 81.5 ± 5.1 ng/ml respectively, P < 0.001). Moreover, the increase in CD146 is positively co-related to the rise of P-selectin in patients with type 2 diabetes. Conclusion: Expression of CD146 and P-selectin in patients with type 2 diabetes is elevated, and they are positively correlated with severity of diabetic nephropathy.