Abstract: OBJECTIVE To evaluate the quality of enzyme-multiplied immunoassay technique(EMIT) for therapeutic drug monitoring(TDM) of tacrolimus, establish the quality control method for TDM of tacrolimus, improve the accuracy of blood concentration monitoring. METHODS to retrospectively evaluate and analysis the quality control results which was accompanying with blood concentration monitoring of tacrolimus in our laboratory during June 2013 to July 2014, established conventional centerline and control limits, and analysis totaling 127 points, including 39 points in a higher concentration, 52 points in a middle concentration, 36 points in a lower concentrations. RESULTS The low, medium and high levels of conventional centerline were 5.21, 9.20, 19.34 ng·mL^-1, respectively; CV were 31.01%, 22.84%, 15.11%, respectively. Levery-Jennings control method detection 1 time out of control. Westgard multi-rules control method detection 6 times out of control. CONCLUSION Westgard multi-rule control methods have a higher error detection rate than Levey-jennings quality control methods. Westgard rules used to determine the quality control results, can improve the reliability of monitoring data, can provide accurate blood concentration monitoring results for clinical use.