Abstract: A great number of fissures were exposed by quarrying during the past 20 years at Xiaoxishan hill (35°27' 30" N, 116°36' 24" E), Pingyi county, Shandong Province. From four of which, many mammal fossils were collected. by the present authors in the spring of 1996. Each fissure or locality has only a single fossiliferous layer. Their stratigraphical correlation are shown in the text figure 1. The mammal complex is composed of 14 genera and 15 species of 13 families belonging to Insectivora, Chiroptera, Lagomorpha, Rodentia, Carnivora and Artiodactyla (see table l), and comparable with those of Locality I and 3 of Zhoukoudian in composition by having 10 of 15 species among them. However, the fact that the mammal complex shares three and two extinct species, Erinaceus olgae, Myospalax wongi and Megaloceros pachyosteus, with those of Locality 1 and 2 of Zhoukoudian respectively indicates they are of the same age or Middle Pleistocene. Lithologically, Locality 1 of Pingyi seems to be comparable to the Layer 1— 3 of Locality I of Zhoukoudian due to the same yellow sandy clay other than reddish clay as in the other layers. If the Uranium Series disequilibrium dating of the layer 1—3, about 230— 290 ka, is reliable, the Locality 1 of Pingyi can be correlated to the L3 of the loess section of Luochuan region. Stratigraphically, Both locality 3 and 4 of Pingyi should be slightly later and the locality 2 earlier than this locality. Ecologically, the fauna of Locality I can be subdivided into three types, desert— dry grassland (64%), shrub—grassland (18%) and wide—spread species (18%). None. of the dwellers of the desert—dry grassland, Ochotona daurica, Myospalax wongi (direct ancestor of M. armandi or aspalax), Cricetulus longicaudatus, Lasiopodomys brandti, Lagurus, Meriones and Vulpes corsac distributes in present Shandong, but all in the southern Nei Mongol Plateau and nearby regions. This demonstrates that a migrating event from north to south took place at that time and local environment was rather dry and cold as in the present Southern Nei Mongol Plateau. The mammals from Locality 3 and 4 reflect a brush—grassland condition with mixture of elements of the northern, the southern and the local dwellers, but those from Locality 2 a forest environment represented by subtropical bats, Hipposideros and Miniopterus.