Abstract: The Chenjiawo fauna includes two stratigraphically distinct groups of mammalian fossils, 14 species of mammals and 4 stratigraphic horizons. They are L5, L6, S6 and L8— S9, representing a wide temporal distribution. The first appearance of Peking Man fauna can be correlated with Event 9 in America and Europe (Repenning, 1987 ) and is marked by the lowest stratigraphic occurrence of Cricetinus varians (LSD ). In northern Europe, Event 9 is believed to have taken place near the end of the Saale glaciation about 500 000 years ago (Bonifay, 1990 Therefore the geological age of the Chenjiawo fauna is between 500 000-1000 000 years B. P. , corresponding to oxygen isotope Stages 14-23. Through the correlation between the solid earth, atmosphere, hydrosphere, and biosphere, the boundary between the Upper and Lower Lishi Formation should be moved to the S4/L5 boundary.