Abstract: Two chronological frameworks for Locality 1 at the Peking Man Site of Zhoukoudian, Beijing are discussed. One is based on the previously published dates using the fission track, U- series , palaeomagnetism and ESR methods. The other is based on the ages recently obtained with the U-series dating of flowstone and the 26 Al/10 Be burial dating.
While both frameworks recognize that the Brunhes-Matuyama Boundary of 0.78 Ma is placed below the 13th layer at Locality 1 of Zhoukoudian, two different ages of about 0.45 Ma and 0.77 ± 0.08 Ma are suggested for the 8-9th layers respectively by these two frameworks, i. e. the difference being as large as 0.3 Ma. Significant changes in lithography, fauna and flora were observed from the 8-9th to the 13th layer, indicating at least one glacial-interglacial cycle. The 26 Al/10 Be burial age of 0.77 Ma for the 8-9th layers would squeeze five stratigraphical layers into a narrow time interval. This is hard to understand.
Factors which may cause systematic errors in the 26 Al/10 Be burial dating are discussed, such as the uncertainty of the half-life of the 10 Be, the uncertainty with the ratio of the production rates of 26 Al and 10 Be, and the complexity and unpredictability of the exposure-burial history of the quartz samples.
Further chronological studies on the Peking Man Site are also suggested.

Key words: Zhoukoudian; Peking Man; Dating of paleoanthropological sites; 26 Al/10 Be burial dating