Objective: To study the clinical effect of Fuzheng Jiedu granule (扶正解毒颗粒, FJG) and its influence on serum nitric oxide (NO), nitric oxide synthase (NOS) and rnicroelements in patients with coronary heart disease who are in long-term contact with nickel. Methods: Sixty patients were randomly divided into two groups, the treated group and the control group, 30 in each group. Conventional Western medicinal treatment was applied to both groups, but to the treated group, FJG was given additionally by oral intake, and the therapeutic course for both groups was 4 weeks. Besides, a health control group was set up with 15 healthy subjects selected from the same area, who had no history of contact with nickel. Clinical symptoms of the patients and changes in their electrocardiogram (ECG) and serum levels of NO, NOS and microelements were observed before and after treatment. Results: The total effective rate on clinical symptoms in the treated group was 93.3% and that in the control group 63.3%, comparison between the two showing significant difference (P＜0. 05); the total effective rate on ECG in the two groups was 90.0% and 56.7% respectively, which also showed significant difference ( P＜0. 05). After treatment, levels of serum NO, NOS, Mg, Zn and Ca increased and those of Ni, Mn and Fe decreased significantly ( P＜0. 05 or P＜0.01) in the treated group, while in the control group, changes in these laboratory indexes were insignificant. Conclusion: FJG could lower the blood nickel level and regulate the unbalance of microelements, help restore serum NO and NOS in persons exposed to nickel and improve the clinical symptoms of patients with coronary heart disease and in long-term contact with nickel.