Fuzzy synthetic judgement was conducted for 20 geological anomalies delineated by 1:50 000 soil survey in the middle and upper reaches of the Yuanjiang River, Yunnan Province. The correct evaluation rate is 100% for Rank-A anomalies. Besides, the inspection of some anomalies with relatively high synthetic evaluation values has led to the discovery of ore deposits (occurrences) of different sizes. It is shown that this method provides a relatively reliable technique for the sieving and appraisal of anomalies in the study area.