Abstract: Objective The present study was conducted to evaluate the measurement capacity of the net laboratories involved in the national (Hong Kong, Macao and Taiwan not included) quality control beyond salt iodine laboratories. Methods The method of standard reference valueuncertainty was used to evaluate the test results. Results All of the 31 provincial salt iodine laboratories returned their results, which were all qualified. The feedback rate from labs at prefectural (city) level was 99.1% with a qualified rate of 96.7%. The feedback rate from labs at the county level was 99.3% with a qualified rate of 97.6%. Conclusion The measurement capacity of the labs at different levels all over the country has been significantly improved through the operation and sustained technical training for 8 years.