通过对城市景观水体什刹前海与罗马湖的调查和监测，分析了北京典型景观水体的水质状况与生态环境特征，探讨了两水体形成透明度差异的原因。监测结果表明，什刹前海东岸透明度达70 cm，而罗马湖透明度为27 cm，分析其差异的主要原因是磷浓度的差异，由此可见，控制磷的浓度是保持城市景观水体水生态系统健康的重要因素。

Through investigation and onitoring to urban landscape waters―Shichaqianhai and Roma Lake, water quality and habitat raits of typical landscape waters in Beijing were analyzed. The differences of transparency in wo lakes were discussed. The results show that, transparency of Shichaqianhai arrives at 70 cm, nd that of Roma Lake is 27 cm, which is because of different phosphorous concentration in two andscape waters. Therefore, phosphorous concentration is a key factor to keep aquatic ecosystem ealth in urban landscape waters.