Objective To observe the clinical effect and possible mechanism of Huotan Huayu Decoction（ 豁痰化瘀方） in treating patients with coronary heart disease without percutaneous coronary intervention therapy. Methods Eighty patients were randomized into a control group（ 36 cases） and a treatment group（ 44 cases）. The control group was given standard treatment

following guidelines for treatment of coronary heart disease. The treatment group was given standard treatment and Huotan Huayu Decoction

one dose every day. Both groups were treated for 30 days. The effect on angina and electrocardiogram in both groups were examined. Quality of life was evaluated with Seattle Angina Questionnaire before and after treatment. Changes of serum homocysteine level were detected. Results For the treatment of angina

the total effective rate was 88. 6% in the treatment group

and 72. 2% in the control group. For the effect on electrocardiogram

the total effective rate was 90. 9% in the treatment group

and 63. 9% in the control group. The effect on angina and electrocardiogram in the treatment group was superior to that in the control group（ P <0. 05）. Results from Seattle Angina Questionnaire evaluation showed that

after treatment

scores of angina stable state

angina attack situation and satisfaction degree of treatment in the treatment group were higher than those before treatment（ P < 0. 05 or P < 0. 01）. After treatment

the scores of angina stable state and angina attack situation in the control group were higher than those before treatment（ P < 0. 01）. After treatment

the score of angina attack situation in the treatment group was higher than that in the control group（ P < 0. 05）. After treatment

serum level of homocysteine in both groups decreased（ P < 0. 01）

especially in the treatment group（ P < 0. 05）. Conclusion Huotan Huayu Decoction combined with Western medicine for patients with coronary heart disease without percutaneous coronary intervention therapy might improve the clinical effect and quality of life. The effect might relate to reduction of the serum level of homocysteine.