Objective：To observe the clinical effect of modified Suanzaoren tang for chronic insomniacs of yin deficiency with effulgent fire type， and to analyze and compare its effect on subjective and objective sleep quality.Methods： In accordance with the inclusion criteria，a total of 70 cases were included and randomly divided into two groups，and 67 cases were included finally.The western medicine group(33 cases)was given estazolam tablets；according to their own conditions，they were recommended to take one tablet at a time before going to bed，and for three to five days a week.The Chinese medicine group(34 cases)was given decoction of modified Suanzaoren tang for one dose per day and each dose was taken twice.Both groups were treated for eight weeks.Results： After treatment，the scores of PSQI in the two groups were significantly improved(P ＜ 0.01)，but there was no significance being found in the comparison of the scores in the two groups(P ＞ 0.05). After treatment，in the western medicine group，the total sleep time and the time of light sleep were increased when compared with those before treatment；the time of rapid eye movement(REM)sleep，the awakening time and the time of first falling asleep were shortened when compared with those before treatment，differences being significant(P＜0.05)；there was no significance being found in the comparison of the deep sleep time before and after treatment in the western medicine group(P ＞ 0.05).After treatment，in the Chinese medicine group，the deep sleep time was prolonged when compared with that before treatment，and the time of first falling asleep was shortened when compared with that before treatment(P ＜ 0.05)；compared with the total sleep time，the time of light sleep，the REM sleep time and the awakening time before and after treatment，there was no significance in the difference(P ＞ 0.05).After treatment，no significant difference was found in the comparison of each index in the two groups(P＞0.05). The treatment for the Chinese medicine group had good safety and fewer cases of adverse reactions than that for the western medicine group.Conclusion：The effect of modified Suanzaoren tang on the improvement of subjective sleep is similar to that of estazolam.As for the improvement of the objective sleep，the difference between the two treatments is not obvious.The mechanism of modified Suanzaoren tang improving sleep may be the adjustment of sleep structure and the increase of deep sleep time.Moreover，compared with estazolam，it is safe in clinical use with fewer adverse reactions.