Abstract: OBJECTIVE To investigate how clinical pharmacists participate in the treatment of cancer pain, and to improve pharmacy services for pain therapy. METHODS Clinical pharmacists joined cancer pain management team, skillfully mastered drug characteristics such as adverse reactions, contraindications, metabolic excretion pathway, and interaction, considered the specific information of patient's, such as age, complications, liver and kidney function, disease history, etc., then clinical pharmacists based on drug instruction and professional literature, discussed with doctors to selecte appropriate drugs for patients. RESULTS Most recommendations and advices from clinical pharmacists were recognized and accepted by physicians, which improved the rationality of the clinical pain treatment, reduced and avoided adverse reactions. CONCLUSION In cancer pain treatment, clinical pharmacists can through analyzing drug characteristics and patients specific conditions comprehensively, then comparing similar drugs to choose the most appropriate drugs for patients.