Tissue culture, biochemical techniques and radioimmunoassay were used to study the effects of Compound Lian Zhu Capsule on micrangium lesions in diabetic rats. The results indicated that blood sugar, glycosylated hemoglobin (GHb), urinary protein and malondialdehyde (MDA) contents, aldose reductase (AR) activity and 3H-TdR incorporation rate in the vascular smooth muscle cell (VSMC) were significantly higher, and plasma NO content in the diabetes mellitus (DM) group were significantly lower than those in the normal control group (both P < 0.05). The above indexes in the Chinese medicine (TCM) treatment group were improved significantly as compared with the DM group, with no significantly differences, except urine volume and urinary protein, as compared with the normal control group. It is suggested that Compound Lian Zhu Capsules cansignificantly alleviate the complicated lesions of the micrangium in diabetic rats.