Objective To investigate the therapeutic efficacy of Chinese medicine of Wusheng Tincture for external application in treating cancer pain, and to observe its effect on the quality of life ( QOL) of cancer patients. Methods Eighty-three cancer pain patients were randomized into treatment group (N=42) and control group (N=41). Except 5 cases dropping out for the itch of skin, a total of 78 cases finished the treatment, 40 in the treatment and 38 in the control group. The patients were given the corresponding medicine according to the classification of numerical rating scale ( NRS) scores. In the control group, the patients were treated following the three-step analgestic ladder issued by World Health Organization ( WHO). The treatment group was given external application of Wusheng Tincture on the painful regions based on the same three-step analgestie ladder treatment as that of the control group, the treatment course lasting 7 days. The rating scale NRS scores and QOL scores were observed for the assessment of therapeutic effect and QOL of the two groups. Results (1) On medication day 7, NRS scores in both groups were decreased as compared with those one day before treatment (P<0.01), but the differences between the two groups were insignificant (P>0.05) . (2) The total effective rate of the treatment group was 82.5%, and that of the control group was 68.4%, the difference being significant between the two groups ( P<0.05) . For mild-pain patients, the therapeutic effect of the treatment group was better than that of the control group (P<0.05) . However, the difference of the therapeutic effect for patients with moderate and severe pain was insignificant between the two groups ( P>0.05) . ( 3) On medication day 7, QOL scores were much lower in both groups than those one day before medication, the difference being significant ( P<0.01) . However, the difference of QOL scores between the two groups was insignificant after medication (P>0.05) . Conclusion External application of Wusheng Tincture may have certain therapeutic effect in treating patients with mild cancer pain, but fails in enhancing the effect for patients with moderate and severe pain, either in improving the QOL of cancer pain patients when used together with WHO three-step analgestic ladder.