OBJECTIVE: To observe the occurrence of paclitaxel(PTX)-induced muscle soreness and therapeutic efficacy and safety of diclofenac sodium. METHODS: Among 84 patients with malignant tumor receiving PTX chemotherapy, 56 patients suffered from PTX-induced muscle soreness, among which 22 female patients suffered from medium and severe muscle soreness and then were randomly divided into group A and B, with 11 cases in each group. Group A was given Diclofenac sodium sustained-release tablet 75 mg orally, once a day; group B was given Paracetamol and tramadol hydrochloride tablets one tablet orally, once a day, and then given Promethazine hydrochloride injection 100 mg subcutaneously, 2-3 times a day when muscle soreness could not be born. Treatment course of both groups lasted for 5 d. The distribution of muscle soreness were observed. The onset time and duration of muscle soreness were also observed as well as pain relief and the occurrence of ADR in group A and B. RESULTS: Among 84 cases, the incidence of muscle soreness was 66.67%, among which mild pain accounted for 23.81%, moderate pain accounted for 13.10%, and severe pain accounted for 29.76%. Among 56 patients with muscle soreness, earliest muscle soreness occurred on the day of medication, and most of muscle soreness occurred on 1-3 days after medication, mainly manifesting as sore, activity limitation when severe, associated with fatigue. The pain relief rate of group A and B were 100%, but the incidence of adverse reactions in group A was significantly lower than group B, with statistical significances (P<0.05).CONCLUSIONS: Diclofenac sodium is similar to paracetamol and tramadol hydrochloride in the treatment of PTX-induced muscle soreness,but it is better than paracetamol and tramadol hydrochloride in safety.