Objective To observe the efficacy and safety of Anshen Decoction（tranquillization decoction

安神汤） for primary insomnia. Methods Totally 120 cases of primary insomnia were randomized into the Chinese medicine group and western medicine group

with 60 in each. Both groups were given sleep health guidance. The patients in the Chinese medicine group were orally taken modified Anshen Decoction twice daily. The patients in the western medicine group were orally taken Estazolam 1 mg to 2 mg per night. The efficacy was evaluated after 4-week treatment. The changes of Pittsburgh Sleep Quality Index（PSQI） were observed before and after treatment. The adverse reactions were recorded. Results The total effective rate of the Chinese medicine group and western medicine group was 84. 48% and 88. 00% respectively

with no significant difference between groups（P > 0. 05）. The total scores and sleep factor scores of PSQI were significantly improved in both groups after treatment（ P < 0. 05 or P <0. 01）. The Chinese medicine group was superior to the western medicine group in shortening the time of falling asleep（P < 0. 05）. The adverse reactions in the Chinese medicine group were significantly fewer than those in the western medicine group（P < 0. 05）. Conclusion The efficacy of Anshen Decoction is similar to Estazolam in treating primary insomnia. But Anshen Decoction can better shorten the time of falling asleep and has fewer adverse reactions.