Xianghu Lake is tropical urban lake, lacated in Zhaoqin city of Guangdong Province, and it has five sublakes which connect each other. The water quality for the four sub-lakes was investigated in 2002. The results indicated that the trophic level in the sublake Bohai was the highest, and followed by sublake: Zhongxin. In comparison with the measurement in 1996-1997, Zhongxin sublake, used to be the lowest sulake in trophic level, changed from mesotrophic to meso-eutrophic. The concentration of Chlorophyll-a was significately relayed to the concentration of NO₃^-, but not with the concentration of PO₄^3-, suggested that NO₃^- may be the main limited factor for primary production. In contrast to the data from 1996-1997, the nitrogen loading in Xinghu Lake increased by 46.5%, phosphorus loading decreased by 40.8%, the concentration of Chlorohylla increased from 6.0mg·m^-3 to 16.9 mg·m^-3.