The spatial distribution, temporal changes of water transparency and their influencing factors in Lake Fuxian, a deep lake in Yunnan Plateau, were analyzed according to the investigations during June-July in 2005 and the regular monitoring data since 1980. The Secchi disk transparency varied from 0.5-6.2m with an average value of 4.6m in Lake Fuxian during June-July in 2005, The spatial distribution pattern of transparency was: north area