Abstract: The proficiency testing results analyzed by robust statistical technique for the determination of As in marine organisms, Cd in marine sediments among 56 marine monitoring or testing laboratories are reported in this paper.Analysis of the results indicates that the majority of the participating laboratories have maintained excellent detection ability and the test data provided by these laboratories are reliable and credible.However, the minority of the testing laboratories are found to have unsatisfactory detection ability.These laboratories are encouraged to take actions to strengthen their laboratory management and quality control, ensuring that the detection ability would be promoted and maintained.In this study, robust statistical technique performs efficiently to evaluate the proficiency testing results of laboratories, authentically reflecting the current detection capacity of laboratories.