Abstract: Abstract: The Gejiu mining area of Yunnan Province is world-famous for tin resources. In total, there are 31 tailing dams in the study area, and the amount of tailings exceeds 190 million tons which could be either further resources or a hazard of contamination. Therefore, it is evidently critical to thoroughly investigate the concentrations and distribution of elements in the tailings and the related controlling factors. In this paper, both geochemical reconnaissance and detailed geochemical survey of tailings were conducted. Totally the work of reconnaissance for 19 tailing dams and the detailed survey for 2 tailing dams were accomplished. The following conclusions have been reached: (1) The material compositions and element concentrations differed significantly between different tailing dams in Gejiu. The distribution of elements in the tailing dams shows anisotropy vertically and horizontally; (2) Types of ores, gravitational segregation and beneficiation have great influence on the distribution of elements in the tailing dams; (3) A suite of methods and techniques for geochemical survey of tailings has been established. (4) The concentrations of Sn, Cu, Fe, Pb, Zn, In, Ga, As and Cd in tailings are high, which implies that more attention should be paid to the great potential value and environmental risks of tailing dams in Gejiu.