Objective To observe the curative effects of Chaizao Decoction（柴枣汤） on insomnia caused by phlegm heat and internal disturbance. Methods A total of 200 insomnia patients were randomly divided into a treatment group and a control group

with 100 patients in each group. The treatment group was treated with Chaizao Decoction

one dose per day. The control group was treated with esazolam

1 mg each time

taking before sleep. The course of treatment was 4 weeks. The changes of Insomnia Severity Index（ISI） scores

Pittsburgh Sleep Quality Index（PSQI） scores

Self-Rating Scale of Sleep（SRSS） score before and after treatment were observed. Results In the treatment group

62 cases were cured

24 cases significantly effective

10 cases effective

4 cases ineffective

with the total effective rate 86%; in the control group

50 cases were cured

10 case significantly effective

38 cases effective

2 cases ineffective

with the total effective rate 60%. The total effective rate of the treatment group was significantly better than that of the control group（P < 0. 01）. ISI

PSQI and SRSS scores of patients in both groups were significantly decreased after treatment. ISI

PSQI and SRSS scores of patients in the treatment group were significantly lower than those in the control group after treatment（P < 0. 05）. Conclusion Modified Chaizao Decoction could effectively improve the sleep quality of insomnia patients caused by phlegm heat and internal disturbance.