Abstract: The BeijingHangzhou Grand Canal is the earliest in excavation, the largest in watershed and the longest in mileage for manmade rivers in the world. Based on the paleobotanical evidence during the Quaternary along the canal, genus and family composition, floristic composition, and ecological function types of the palynoflora were analyzed in this paper. The Quaternary vegetation was reconstructed. The results are as follows: There are 105 families of land plants recognized. Temperate floristic elements can be viewed as the basic framework in this flora, with temperate and tropical transitional nature. This flora also reflect the following environmental fluctuations, e.g. alternation of wet and dry conditions, replacement of warm and cold climate, and mosaic of land and water environment. The index of point diversity is 22—68 families(genera) in the north, and 65—117 in the southern. Palynoflora along the canal can be divided into 13 types of ecological function. Along the canal, the midHolocene forest vegetation, from north to south, can be divided into four categories: cooltemperate mixed coniferous and deciduous forest zone, temperate deciduous broadleave forest zone, warm temperate evergreen and deciduous broadleave forest zone, and subtropical evergreen broadleave forest zone. The main factors affecting the Quaternary vegetation change along the canals are the Tertiary plant residues, Quaternary climate change and early human activities.