Abstract: Located in the marginal belt of the southeast monsoon and ecotone, Daihai Lake has always been one of the most significant areas in the studies of paleoclimate change.Environmental proxies, such as TOC,δ¹³C org , carbonate contents, frequency dependent susceptibility and ostracoda fossils of sediment from Daihai Lake, Inner Mongolia, had been employed to reconstructed the paleoclimate evolution during the past thousand years.The environmental multiproxies indicated the cold humid climate, rather than cold dry climate in the early stage of the Little Ice Age(LIA).The last two cold periods of the LIA, recorded by the sediment, were in good agreement with those deduced by tree rings, ice core and historical literature.Based on the climate features in the last hundred years, this paper also advanced that human activities had become the main reason of the lake environmental deterioration in recent years.