Based on the pollen combination, 14C dating, and depositional facies analysis of Momoge profile in Zhenlai County, Jilin Province, three pollen belts were divided. The results showed that Momoge Lake was formed by blocked paleo-river course depression 1500 years ago, which included three development stages, i.e., the period when river converted into lake, the early period of lake development, and the steady period. Its corresponding plant types were Artemisia-Chenopodium grassland, Artemisia-Chenopodium grassland accompanied by Betula, and meadow grassland, and its paleo-climate was dry-cold, warm-dry, and then cool-wet, and there was a warm-dry tendency in recent fifty years.