ObjectiveTo observe the therapeutic effect of Xuanbi Tongluo Decoction（decoction to diffise impediment and free the network vessels） on stable angin a pectoris and its effect in anti-free radical damage and protecting the ischem ic myocardium.MethodsTotally 124 cases of stable angi na pectoris were randomize d into isosorbide dinitrate（ISDN） group of 41 cases

Xuanbi Tongluo Decoction group of 40 cases and combo therapy group of 43 cases.The therapeutic effect and the levels of superoxide dismutase（SOD） and malondialdehyde（MDA） were observed be fore and after treatment and were compared with 35 healthy subjects.ResultsThe total effective rate of the Xuanbi Tongluo Decoction group

the ISDN group

and the combo therapy group

was 85.00%

73.17% and 88.37% respectively.The total effec tive rates of the Xuanbi Tongluo group and combo therapy group was superior to that of the ISDN group（P<0.05）.There was no significant difference in the total effective rate between Xuanbi Tongluo group and combo therapy group（P>0. 05）.Before treatment

the activity of SOD in angina patients was lower than that in the healthy（P<0.05）

and the level of MDA in angina patients was higher than that i n the healthy（P<0.05）.The activity of SOD was significantly increased and the level of MDA was significantly decreased in the Xuanbi Tongluo Decoction group a nd the combo therapy group after treatment（P<0.05）.There was no significa nt di fference in the activity of SOD and level of MDA between before and after treatm ent in the ISDN group（P>0.05）.ConclusionXuanbi Tongluo Decoction could effect ively relieve the attack of stable angina pectoris

which may be relevant to pre venting SOD and inhibiting MDA.