第四纪在全球性冰期和间冰期气候影响下，甘肃气候呈干旱、寒冷与温暖、湿润交替变化。沉积物以灰色格调为主，水平和垂直分带规律明显，成因类型复杂。各地区在小气候影响下植被发育不平衡。总的看来，以干旱区系草本植物为主，喜温暖湿热的木本植物较少，一般呈荒漠草原型和疏林草原型，局部为森林草原型。动物群的分布和古人类的发展受古地理环境影响：早更新世早期以大型哺乳动物为主；早更新世晚期和中更新世以穴居的鼠兔类为主；晚更新世以干旱—半干旱草原型动物群为特征；全新世在适宜条件下人类文化得到发展，部分野生动物在人类豢养下成为家畜 Quaternary Gansu climate is arid, cold and warm, wet alternate under the influence of the global glacial and interglacial climatic changes. Sediments dominated by gray style, horizontal and vertical zoning obvious rules, causes of complex types. Vegetation is unevenly developed in all regions under the influence of microclimate. In general, the herbaceous plants in the arid area are the main ones, while the woody plants that prefer warm, humid and warm are less. They are generally desert grassland-type and sparse-forest grassland type, and some are of the forest grassland type. The distribution of fauna and the development of ancients were influenced by the paleogeographic environment: the early Pleistocene was dominated by large mammals; the late Pleistocene and Middle Pleistocene were dominated by burrowing rabbits; the late Pleistocene was dominated by arid-half Arid steppe type fauna; the Holocene developed under the appropriate conditions of human culture, some of the wildlife in the raising of human beings to become livestock