By analyzing the 137Cs and grain-size samples, along with the results of field investigation and some other relevant materials, the total amounts of 137Cs deposition by wind and water in the Dalian Lake of Gonghe Basin, Qinghai Province is defined. The vertical profile of 137Cs in the lacustrine sediments has exhibited three 137Cs activity peaks and one valley: the maximum peak corresponds to the global 137Cs fallout in 1963; the two secondary peaks correspond to the leakage of the Chernobyl reactor in 1986 and complete desiccation of the lake in 1994 respectively; while the valley corresponds to aeolian deposition caused by the extensive reclamation in late 1980s and early 1990s. The 137Cs dating was used to evaluate the average sedimentation rate of Dalian Lake since 1963, Consequently, the deposition processes are divided into three stages: two slow deposition of 1963-1986 and 1994-1998, and one rapid deposition during 1986-1994. This preliminary study reveals that the 137Cs has the same tracing potential indicating the environmental changes and human interference in the arid and semiarid regions as in the humid region.