Abstract：Objective：To observe the clinical effect of modified Xiaochaihu tang combined with Gualou Honghua powder for postherpetic neuralgia(PHN). Methods：A total of 100 cases of PHN patients were selected and divided into the control group and the observation group according to the random number table method，50 cases in each group. The control group was given symptomatic treatment with routine western medicine，and the observation group was additionally treated with modified Xiaochaihu tang combined with Gualou Honghua powder based on the treatment of the control group. Both groups were treated for four weeks. The scores of Visual Analogue Scale(VAS) and the levels of T cymphocytes subsets including CD3+，CD4+，CD8+ and CD4+/CD8+ before and after treatment in the two groups were compared；clinical effects and safety in the two groups were evaluated. Results：The total effective rate was 92.00% in the observation group and 76.00% in the control group，the difference being significant(P＜0.05). Before treatment，there was no significant difference being found in the comparison of VAS scores between the two groups(P＞0.05). After treatment， VAS scores in the two groups were decreased when compared with those before treatment，and the VAS score in the observation group was lower than that in the control group， the difference being significant(P＜0.05). Before treatment， there was no significant difference being found in the comparison of the levels of CD3 + ， CD4 + ， CD8 + and CD4 +/CD8 + between the two groups(P＞0.05). After treatment，the levels of CD3 +，CD4 + and CD4 +/CD8 + in the observation group were increased when compared with those before treatment and higher than those in the control group，and CD8+ level was decreased and lower than that in the control group(P＜0.05)；the levels of CD3 +，CD4 + and CD4 +/CD8 + in the control group were increased when compared with those before treatment(P＜0.05). The total incidence of adverse reactions was 6.00% in the observation group，lower than that of 14.00% in the control group，the difference being significant(P＜0.05). Conclusion：Modified Xiaochaihu tang combined with Gualou Honghua powder for PHN can improve the clinical effect，and provide reference for the clinical treatment of PHN.