Abstract: OBJECTIVE To evaluate the usability of a performance assessment method of clinical pharmacists. METHODS Evaluate some factors of the performance assessment method of clinical pharmacists flexibly based on Failure Mode and Effect Analysis. These factors included the effectiveness and efficiency of the pharmacists' service, the completion of quantification indicator, satisfaction of the patients, cognition level of inpatient area. Then the usability level of the factors was evaluated, and the projects with lower scores was improved. RESULTS An example for evaluating usability of the performance assessment method of clinical pharmacists is presented to show the application and rationality of the proposed approach. Pharmacists could be urged to focus on improving the quality of work in combination with projects with relatively low PL value. CONCLUSION This method has an positive and fair effective and great benefits to the improvement of clinical pharmacists' ability.