Abstract:Multi-temporal remote sensing image data over the periods from 1985 to 1986, from 1995 to 1996, from 2004 to 2006, and from 2014 to 2015 were used to construct a classification tree(CT)model for aquatic vegetation. With consideration of the differences in phenological information of submerged vegetation in Taihu Lake, the succession of the dominant species of submerged vegetation in the lake over the last 30 years was studied. The overall accuracies and Kappa coefficients of the remote sensing classification results for the four periods were 64. 86% and 0. 59, 70. 83% and 0. 65, 63. 93% and 0. 50, and 64. 94% and 0. 60, respectively. The results show that Potamogeton malaianus has expanded from Dongshan Bay to Xishan Island, and from East Taihu Lake to South Taihu Lake from 1985 to 2015. There was a declining trend in the growth of Vallisneria spiralis in the Zhushan and Meiliang bays. There was only one kind of submerged vegetation(i. e. , Potamogeton orispus)in Meiliang Bay in recent years. No submerged vegetation was found in the central part of the lake. The submerged vegetation was widely distributed in East Taihu Lake, with the most species. The submerged vegetation has experienced the following four stages of succession in the last 30 years: Vallisneria spiralis-Potamogetonaceae, Potamogeton pusillus, Ceratophyllum Demersum-Elodea nuttalli, and Potamogetonaceae-Elodea nuttalli. Eutrophication and aquatic breeding are the main factors leading to the succession of submerged vegetations in Taihu Lake.