Natural water regime is important for the germination, growth and distribution of aquatic plants. In order to restore the macrophytes of the Chaohu Lake, field investigations were conducted in 2010-2012, hydrological data were also collected for analysis. The results showed that macrophytes of the Chaohu Lake have changed greatly after disconnection from the Yangtze mainstem, and the alteration of natural water level fluctuation (WLF) was the primary factor. After disconnection, the water level of January March was controlled and maintained at a higher level; while that of April June was gradually decreased due to irrigation and flood control. Such a water level regime is completely opposed to the natural condition, and is unfavorable to the germination and growth of macrophytes. Combined the life history with hydrological data, we then analyzed the water level requirements of macrophytes in different life history stages. Based on the water demands of agriculture, industry, shipping and others, we developed specific measures for water level regulation, and tested using water budget equation. The results of this study should be useful for the recovery of aquatic vegetation in other similar regulated lakes. (C) 2014 Elsevier B.V. All rights reserved.