3 native grasses (Cynodon dactylon , Trifolium repens , Festuca arundinacea) in Yixing were selected to construct buffer strips by self-designed experiment facility. The purification efficiency of different sward buffer strips to local runoff and seepage pollutants was investigated through the simulation of agricultural non-point pollution and rainfall characteristics in Yixing. The results showed that the 3 buffer strips could capture suspended solids (SS) in runoff effectively, the SS removal efficiency followed the order of Cynodon dactylon buffer strip> Tri folium re-pens buffer strip> Festuca arundinacea buffer strip> blank group (with no grass plant on soil). The removal efficiency of TN, NH3-N and TP in seepage of sward buffers was significantly better than that in runoff (p<0. 05). All 3 sward buffer strips achieved the most obvious purification efficiency in the first 0. 9 m. The pollutant removal efficiency of buffer strip was proportional to its width. There was a significant positive correlation between sward bio-mass and pollutant removal efficiency. The biomass of Tri folium repens and Cynodon dactylon buffer strip was significant larger than that of Festuca arundinacea buffer strip, correspondingly, their purification efficiency was better that of Festuca arundinacea one.%选择宜兴地区常见的3种草皮百慕大(Cynodon dactylon)、白花三叶草(Trifolium repens)、高羊茅(Festuca arundinacea),利用自行设计的实验装置模拟构建草皮缓冲带,并模拟宜兴地区降雨时产生的汇流过程和雨量进行太湖缓冲带对陆域面源污染物的净化效果研究.结果表明,草皮缓冲带能有效地截留径流中的SS,3种草皮缓冲带的径流对SS的去除率为百慕大缓冲带＞三叶草缓冲带＞高羊茅缓冲带＞空白对照(不种植草皮的空白土壤),且沿程去除效果增强；草皮缓冲带的渗流对TN、NH3-N、TP净化效果均显著(p＜0.05)高于径流；3种草皮缓冲带在试验槽前0.9m处的污染物去除效果最为明显,湖泊缓冲带的宽度与其污染物截留效果呈正比；总体来说,草皮生物量与其构建的湖泊缓冲带的污染物去除率呈正相关,三叶草和百慕大有较大的地上生物量,其构建的缓冲带表现出较高的污染物去除率,而高羊茅的地上生物量相对较小,其构建的缓冲带污染物去除率也相对较低.
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