Abstract: Abstract: Fluid-geological mapping is a new method employed for geological investigation and mineral exploration. The first test of fluid-geological mapping in China was carried out in the Weishan-Yongping copper-gold-polymetallic mineralization district, Yunnan. The authors studied mineralization-controlling geological factors, characteristics of various major deposits (occurrences), ore fluid subsystems and its drainage area, salinities, homogenization temperatures, gas-liquid phase compositions of fluids, trace element contents and stable isotope features of ore fluids, and concentration centers of ore fluid systems in the mineralization district. The fluid-geological map shows the nature and state of ore fluids in the area and the basic characteristics of two ore fluid subsystems. The drainage area and seven concentration centers of the two ore fluid subsystems have been delineated. The distribution of these concentration centers essentially coincides with the distribution of the known mineralization occurrences, geochemical anomalies and favorable geological conditions; therefore they are thought to be an important basis for mineral exploration. This study suggests that fluid-geological mapping is an effective means for mineral exploration.