The Daihai Lake is located in the east margin of semiarid region and thenorth margin of the East Asia summer monsoonThis region is sensitive to the changes of climate and environment，thus being very suitable for the studyof environmental changes The pollen analysis of 65 surface sediment samples from the Daihai Lake and alluvia from its inflow rivers showed the characteristics of modern pollen distribution in the Daihai Lake and different transport vectors fordifferent pollen types Most of the pollen grains in the Daihai Lake came from regionalpollen types，and the pollen assemblages coincided with the regional vegetation However the variance of pollen assemblages in different parts of the lake reflected the changes of local vegetation to some extentAffected by the deposition environment，pollen concentration in the lake surface sediment was lower than that in fresh alluvia of its inflow rivers，and the highest pollen concentration appeared in the central part of the lake Most of the pollen grainsand spores in the Daihai Lake came from their inflow rivers，while the influenceof wind cannot be ignoredInsect，bird and human activities also played a roleMost pollen grains of Artemisia，Chenopodiaceae，Betula，Ostryopsis andsporescame from their inflow rivers，while Pinus，Graminaceae and Cyperaceae pollen grains came from both their inflow rivers and the transport of wind Some other herbs，such as Leguminosae，Crucifereae and so on，may be carried into the lake by insect，bird or human activities DCA analysis supported the conclusions