Aim This report presents the studies of sera levels of lipoprotein (Lp)(a) and phenotypes of apolipoprotein (a) in type 2 diabetes mellitus. The aims of this study were to explore the relationship between aged patients with type 2 diabetes mellitus and sera levels of Lp (a) and the distributive characteristics of genetic phenotypes of apo (a). Moreover the report present the studies the relationship sera levels of Lp (a) and the complications of the aged type 2 diabetic patients with hypertension or retinopathy or nephropathy. Methods Enzyme linked immunosorbent assay (ELLSA) was used to measure sera levels of Lp (a). The phenotypes of apo (a) were determined by SDS polyacrylamide gel electrophoresis (SDS PAGE) and Western blot analysis. Results and Conclusion 1. There was no significant difference in serum Lp (a) concentration among the three groups (P>0.05,respectively). Serum Lp (a) concentration did not significantly correlate with the levels of serum TC,TG,LDLC,HDLC,apo A,apo B (P>0.1,respectively). 2. In the aged type 2 diabetic patients with hypertension or retinopathy or nephropathy, the level of serum Lp (a) concentration was higher than that in patients without these complications (P<0.05 andP<0.001). 3. A total of 7 different phenotypes of apo (a) were determined among the three groups. The aged type 2 diabetic patient with complications mostly had S1 and S2 phenotypes than other groups and the aged type 2 diabetics without the complications.