Abstract: Objective To evaluate the quality of tuberculosis (TB) sputum smear and sputumexamination in TB lab in Tai Zhou City, and to improve the quality of the sputum examination.Method According to the Handbook of Quality Assurance of Sputum Examination, Chinese Tu-berculosis Prevention and Control Plan, the field evaluation and blind rechecking of TB lab werecarried out. Result Rechecking coincidence rate was 98.6%, positive coincidence rate was96. 1 %, negative coincidence rate was 99. 1 % , coincidence rate of general hospital was 98. 9% , andcoincidence rate of TB dispensary was 98. 1 %. Sputum smear quality index included the coincidencerates of sputum cell, size, thickness, dyeing and shedding, which were 89. 5%, 69. 5%, 72. 9%,91. 5% and 97. 4% respectively. For the field evaluation, the pre-job training for the TB lab techni-cians in TB dispensary was stable, the room for TB lab, the equipment and the maintain of the spu-tum smears in TB dispensary were better than the lab in general hospitals. Conclusion Blind re-checking of EQA and field evaluation are effective Methods to identify the problems and rectify theexisting mistakes.

Key words: blind rechecking, sputum smear, external quality assurance, field evaluation, coincidence rate