目的　观察排钱草及三草胶囊对超氧阴离子自由基 (O·-2 )清除率的影响。方法　将排钱草醇提液和三草胶囊水提液分别加到TEMET -AP系统中 ,用比色法测定并计算O·-2 含量和O·-2 清除率 ,并与维生素C的O·-2 清除率比较。结果　排钱草、三草胶囊和维生素C对O·-2 均有明显的清除作用 ,且随加入量的增加对O·-2 清除率升高 (相关系数分别为R =0 .97,R =0 .94,R =0 .93)。但各药物之间的O·-2 清除率有明显差异 (P <0 .0 1 )。结论　排钱草和三草胶囊对O·-2均有明显的清除作用 Objective To observe the effect of Paiqincao and Sancao Capsule on the clearance rate of superoxide anion radical (O·-2). METHODS: The extracts from D. chinensis extract and Sancao capsule were separately added to the TEMET-AP system. The colorimetric method was used to determine and calculate the O.-2 content and the O.-2 clearance, and the O ·-2 Comparison of clearance rates. RESULTS: Paiqincao, Sancao capsule and vitamin C all had obvious scavenging effect on O·-2, and the clearance rate of O·-2 increased with the increase of the amount (correlation coefficients were R=0.97,R respectively). =0.94,R =0.93). However, there was a significant difference in O-2 clearance between the drugs (P < 0.01). Conclusion Both Pai Qiancao and Sancao capsule have obvious scavenging effect on O·-2