Abstract： Objective： To observe the effects of modified Xiaoqinglong Decoction combined with Compound Methoxyphenamine on traditional Chinese medicine syndrome scores and fractional exhaled nitric oxide （FeNO） levels in patients with post-infectious cough （PIC） of pathogenic cold latent in lung type. Methods：A total of 90 patients with PIC of pathogenic cold latent in lung type admitted to Yuyao Hospital of Traditional Chinese Medicine from January 2023 to March 2024 were selected and divided into the control group，the observation group，and the combination group， according to the random number table method， with 30 cases in each group. The control group received Compound Methoxyphenamine treatment，the observation group received modified Xiaoqinglong Decoction treatment， and the combination group received modified Xiaoqinglong Decoction combined with Compound Methoxyphenamine treatment. The clinical efficacy in the three groups was compared； the changes in traditional Chinese medicine syndrome scores，FeNO levels，and the Leicester Cough Questionnaire in Mandarin-Chinese （LCQ-MC） scores in the three groups were compared before and after treatment. Results：The total clinical effective rate in the combination group was 96.67% （29/30），which was higher than that of 70.00% （21/30） in the control group and that of 73.33% （22/ 30） in the observation group， the difference being significant （P＜0.05）. After treatment， the traditional Chinese medicine syndrome scores in the three groups were decreased when compared with those before treatment （P＜0.05）， with the combination group showing lower scores than the observation group and the control group （P＜0.05）. After treatment，FeNO levels in all three groups were decreased when compared with those before treatment （P＜0.05），and the combination group had lower FeNO level than the observation group and the control group （P＜0.05）. After treatment，LCQ-MC scores in all three groups were increased when compared with those before treatment （P＜0.05）， with the combination group scoring higher than the control group and the observation group （P＜0.05）. Conclusion： Modified Xiaoqinglong Decoction combined with Compound Methoxyphenamine can effectively alleviate clinical symptoms，reduce airway hyperresponsiveness，and improve quality of life in patients with PIC of pathogenic cold latent in lung type.