Abstract: Objective　To investigate the reasonable acceptable range of external quality assessment of quantitative polymerase chain reaction（PCR） for hepatitis B virus（HBV） DNA detection， and make the external quality assessment more truly reflect and monitor the detection capabilities of clinical laboratories. Methods　Shanghai Center for Clinical Laboratory arranged a flight check for HBV DNA with 5 quality control samples，which were distributed to 51 participating clinical laboratories. After 3 hours，the test results of all participants were brought back and analyzed by investigator. The reagents were classified into A， B and C groups， according to the number of hospital using ≥10. The results，group mean values， sample standard deviations（s） ith different concentrations and coefficients of variatio（CV） among various reagent groups were compared， respectively. The value of logarithm±0.4 calculated from group mean value±3s， group mean value±0.5log10 and test values traceable to national standards was used to evaluate the detection results of clinical laboratory. Results　The detection results of clinical laboratories among various reagent groups had significant difference. Compared with the B reagent group，the A reagent group detection results of sample 1142，1144 and 1145 were statistically significant（P<0.05）. Compared with the C reagent group， the A reagent group detection results of sample 1144 and 1145 were statistically significant（P<0.05）. When comparing the A reagent group mean value with the B and C reagent group mean values，or the test values traceable to national standards （the results indicated as logarithm value， and the unit was IU/mL）， the difference of sample 1144 and 1145 exceeded 0.4，and the sample s and s and CV of 4 different concentration samples all exceeded the sample s and CV with an allowable total errors of 0.4. The pass rates of participating laboratories which were evaluated by the 3 kinds of Methods were 100%，88.2% and 64.7%， respectively. Conclusions　The mean value±3s used for acceptable range of external quality assessment of the quantitative PCR for HBV DNA detection is more reasonable， and can truly reflect and monitor the detection capabilities of clinical laboratories.

Key words: Hepatitis B virus, DNA, Polymerase chain reaction, External quality assessment, Acceptable range