Abstract: OBJECTIVE To investigate the effect of sodium fusidate on detections of serum TBA. METHODS Serum TBA were detected using the circulating enzymatic method. Distilled water was treated as a blank control, the amount of TBA was analyzed in different solutions as follows: serum, different concentrations of the mixture of sodium fusidate and distilled water, different concentrations of the mixture of sodium fusidate and serum. Each solution was analyzed triplicatedly. RESULTS The average serum TBA was 4.4 μmol·L^-1. However, the average results of TBA in the mixture of sodium fusidate and distilled water and in its dilutions of 2, 4, 8, 16 times were 215.36, 126.41, 75.12, 36.78, 19.65 μmol·L^-1, respectively. Correspondendly, the average results of sodium fusidate serum mixture and its 2, 4, 8, 16 times dilutions were 222.47, 133.92, 83.26, 43.31, 23.58 μmol·L^-1, respectively. CONCLUSION The assays desmontrate that sodium fusidate could severely affect the detection of serum TBA and give rise to significant increases. Therefore, it is suggested that those patients who need to check their liver functions should stop using sodium fusidate before doing the tests.