Lakes in Yunnan Plateau have undertaken tremendous change due to human activities, especially since 1980s. For the sake of the environmental protection, especially eutrophication control on the main lakes in Yunnan Plateau, the thresholds of different indexes such as transparency and chl. a concentration in lakes are suggested, two of which are not explicitly included in national water quality standards (GB3838-2002) of China. The suggestions offered are obtained based upon document analysis on relevant standards from local and abroad and investigations from typical lake regime in Yunnan Province. For water transparency, the values could be 5.0 m for Grade I, 2.5 m, 1.0 m and 0.5 m for Grade II, HI, IV-V (according to GB3838-2002) respectively. For chl. a, they could be 2 μg/L, 10μg/L,20μg/L,40μg/L and 60μg/L for Grade I, II, M, IV, V respectively. The thresholds suggested could be a substantial implementation of national standard (GB3838-2002) for local management guidance.