Abstract: Analysis were made on annual water level variation, precipitation evaporation during 1960-2016, as well as on daily water level variationduring 2008-2016 in Thousand-island Lake, Zhejiang province. The results showed that the maximum water level was 108.41 m, and the lowest was80.00 m. The mean water level fall of the reservoir was 26.69 m from 1959 to 1979, 22.09 m from 1980 to 1999, and 14.14 m from 2000 to 2016.Mean monthly water level decreased first, then gradually increased and decreased from January to December during 1960-2016, with the lowest inFebruary, and the highest in July. The withered water period of the reservoir was from January to March, wet season from June to October, and theleft months normal. The change of water level had been affected by precipitation, evaporation and human activities. Based on analysis on naturalvertical plant distribution, experiments were conducted from the winter of 2016 to the spring of 2017 on planting saplings of Salix chienii,Taxodiumascendens, Metasequoia glyptostroboides, Nyssa aquatic, Liquidambar formosana, Pterocarya stenoptera at terraced field of the lake. Investigationsshowed that trees were survived and plantation should be higher than 100 m of water level in the lake. The technique for afforestation at terraced fieldaround the lake could be extended for similar places in Thousand-island Lake.