Abstract：Objective：To observe the clinical effect of modified Anshen tang for patients with insomnia of depressed liver qi transforming into fire type and its effect on 5- hydroxytryptamine(5- HT)，dopamine(DA) and γ- aminobutyric acid(GABA). Methods： A total of 98 cases of patients with insomnia were divided into the control group and the observation group according to the random number table method，with 49 cases in each group. The control group was treated with estazolam tablets，and the observation group was additionally treated with modified Anshen tang based on the treatment of the control group. Chinese medicine syndrome scores， Pittsburgh sleep Quality Index(PSQI) scores， polysomnography monitoring indexes and levels of 5- HT， DA and GABA before and after treatment as well as clinical effects in the two groups were compared. Results：The total effective rate was 89.80% in the observation group，higher than that of 77.55% in the control group(P＜0.05). After treatment，PSQI scores，Chinese medicine syndrome scores and DA levels in the two groups were decreased when compared with those before treatment(P＜0.05)， the total sleep time was prolonged(P＜0.05)， sleep efficiency and levels of 5-HT and GABA were increased(P＜0.05)，and sleep latency was shortened(P＜0.05). After treatment， PSQI score，Chinese medicine syndrome score and DA level in the observation group were lower than those in the control group(P＜0.05)，the total sleep time was longer(P＜0.05)，sleep efficiency and levels of 5- HT and GABA were higher(P＜ 0.05)，and sleep latency was shorter(P＜0.05). Conclusion：Modified Anshen tang has a significant clinical effect in treating insomnia of depressed liver qi transforming into fire type，which can significantly reduce Chinese medicine syndrome scores and PSQI scores，improve polysomnography monitoring indexes and regulate monoamine neurotransmitter levels.