Abstract: According to the proficiency testing program (CNCA-13-A14) held by the National Certification and Accreditation Committee of China (CNCA), analytical data for W, Sn, Cu, Pb, Zn, Mo, Sb and Bi in tungsten and tin ores provided by 58 analytical laboratories in 30 provinces and autonomous regions were evaluated. Robust statistics, an international general statistical method, and Z-scores were used for evaluating the testing ability of the laboratories. According to the criteria for satisfactory results (Z-scores ≤2), the overall satisfaction rate for 58 laboratories was 88% (51 laboratories) and 12% of laboratories had suspect and outlier results. As a whole, the satisfaction rate for Sb, Pb and Zn in tungsten and tin ores was high, among which all of the analytical results of Zn in Tin Ores were satisfactory; results of W, Bi were slightly worse. Results of tungsten were better than those for tin ores. Moreover, the determination methods in all laboratories and the reasons for the outlier results were analyzed. The results of proficiency testing were objectively reflected for the testing ability and technical levels of the geoanalytical laboratory. Due to the determined gap among different laboratories, it was suggested that proficiency testing should be held periodically to improve the analytical ability and ensure the reliability of analytical data.