中文摘要：

西辽河地区史前和历史时期文化发达，分别发育了小河西文化-兴隆洼文化-赵宝沟文化-红山文化-小河沿文化-夏家店下层文化-夏家店上层文化，这些文化的兴衰同环境的演变密不可分，旱作农业的起源有可能在西辽河地区。西辽河地区古代环境、与人类文明发生以及演变关系一直是研究的热点，本研究将采自赤峰地区红山水库厚度为155cm的自然剖面进行了测年、孢粉和粒度分析，得到晚更新世末期西辽河地区古植被以及古环境资料。粒度分析说明沉积环境可能为河漫滩。孢粉分析结果显示：晚更新世末期进入全新世前，西辽河地区较现代温暖湿润，植被是草原植被，主要的植物是蒿属以及菊科的其他植物，河漫滩中生长有香蒲属植物，不远的山地分布有疏林，针叶树主要是松、云杉和铁杉，而阔叶树主要是桦木科、胡桃属、栎属和榆属。自下而上，将剖面分为4个孢粉组合带（Zone 1～4）。Zone 1（15280～14680cal．aB．P．）和Zone2（14680～14090cal．aB．P．），针叶树主要是云杉和铁杉，而阔叶树主要是桦木科和胡桃属植物；Zone2，盘星藻大量增加；Zone3（14090～13890cal．aB．P．），除了云杉和铁杉，松属也是主要的针叶树种类，此时香蒲的数量急剧增加；Zone4分为2个亚带，即Zone4—1（13890～13670cal．aB．P．）和Zone4—2（13670～13110cal．aB．P．），Zone4主要的针叶树为松-云杉，此时的阔叶树也变为落叶栎-榆属。在Zone4—2，伴随着C／A值的增大，铁杉花粉消失。铁杉花粉消失在约13610cal．aB．P．，可能是由气候的干旱引起。相对温暖湿润的气候环境为农业的发生提供了丰富的野生资源，而后期环境趋于干旱，这可能是促使农业发生的一个因素。

英文摘要：

Human cultures flourished during the prehistoric and historic periods in the Western Liao River Region, witnessed by the Xiaohexi Culture, Xinglongwa Culture, Zhaobaogou Culture, Hongshan Culture, Xiaoheyan Culture, Lower Xiajiadian Culture and Upper Xiajiadian Culture and formed a continuous cultural sequence in this region. The appearance and disappearance of each of these cultures were related to environmental changes. It has been assumed that millet agriculture might have originated in the Western Liao River Region. However,the environment before the Holocene in this region remains to be clarified. In the present paper a profile located to the north of the Hongshan Reservoir in Chifeng, Inner Mongolia was investigated. This profile, about 155cm in thickness, was sampled every 3 -4cm, and was dated using optically stimulated luminescence（OSL） and radiocarbon methods. Results showed that the sequence was deposited during the period of 15280cal. aB. P. to 13110cal. aB. P. Palynological analysis and grain size analysis were undertaken. Grain size analysis demonstrated that the sediments were deposited on a floodplain. The palynological analysis indicated that the paleovegetation consisted of grassland and a steppe with Artemisia and other types of Compositae. Typha grew on the floodplain,which was surrounded by open forest. Pinus,Picea and Tsuga were the main conifers in the open forest. Four pollen zones were established from the bottom to the top. In zones 1 （ 15280 - 14680cal. aB. P. ） and 2 （ 14680 - 14090cal. aB. P. ）, the main conifers were Picea and Tsuga,while the broad-leaved arboreal vegetation consisted of pioneers, such as Betulaceae and Juglans, while Pediastrum increased in Zone 2. In Zone 3 （14090 - 13890cal. aB. P. ） , Pinus became more common and Typha,an aquatic plant,increased dramatically. Zone 4 could be divided into two subzones,Zone 4-1 （13890 - 13670cal. aB. P. ）and Zone 4-2 （13670 - 13110cal. aB. P. ）. In Zone 4, the main conifers were Pinus- Picea,while the broad-