Abstract: According to the characteristics of spore-pollen assemblages from six section of the Song-nen plain and C¹⁴ dating. Since late period of the latepleistocene, the vegetational succession divided into six stage. Stage Ⅰ. (60000-30000 yr.) The formation is characteristed by dark co-niferous forest-steppe, Which mainly consists of Pinus, Picea, Chenopodiaceae.Artemisia and accompany Botrychum, Lycopodium. That time climate was cold and humic. Stage Ⅱ. (30000-21000 yr.) The formation is dominated by theropeu-cedrymion-steppe or brich forest-steppe. In which, Pinus, Betula, Artemisia or Betula and Artemisia is dominated, At that time, the climate was mild andcold. Stage Ⅲ. (21000-11000 yr.) The formation is dominated by dry steppeor open steppe or weed. Which has Chenopodiaceae, Artemisia or Pinus and Chenopodiaceae. Vegetation rare. The climate was dry cold. Stage Ⅳ (11000-7500 yr.) The formation is dominated by theropeuced-rymion, rare forest-meadow or meadow-steppe. In which, Pinus and. Betula ispredominated. On the middle plain, increase of the decidous broad-leavedtree. The climate was mild and slight humid. Stage Ⅴ. (7500-2500 yr.) The formation is dominated by decidousbroad-leaved forest, forest-meadow or forest-steppe.Which mainly consists of Pinus, broad-leaf tree. Cyperaceae and Artemisia. The species has Juglans, Tilia, Carpinus and a lot of Cyperaceac. The swamp is developed. Peat isaccumulated. The climate was warm, moist. Late period the climate slightcold. Stage Ⅵ. (2500-Present) The formation is dominated by the conifrousforest. theropeucedrymion or meadow-steppe. The climate resemble recent. It is proved C¹⁴ dating and fossil of the vertebrate. Stage Ⅰ-Ⅲ belongto late period of the late Pleistocene. Stage Ⅳ belong to early Holocene.Stage Ⅳ belong to middle Holocene, Stage Ⅵ belong to Late Holocene. During late period of the late pleistocene, due to it is influenced bythel ow temeperate weather from terrestric glacier of the Sibirica. All the North-East plain by control of the preglacier climate, it is cold and grown a lot of xerophytes, formed an especial plant association. its contain treepollens:Pinus, Picea, Betula. Herb pollen:Chenopodiaceae, Compositae, Gramineae and Spores of fern:Botrychum, Selaginella, Locopodium. That late period of the late pleistocene, the vegetational type arethree model vegetational landscape of the preglacier and sporepollen ass-emblages is model assemblage under preglacier climate also. Its was one ofthe symbol layer of late pleistocene.