In the present study, the author intended to investigate whether Gamiyukgunja-tang (Jiaweiliujunzi-tang, GYGT) significantly affect both mucin release from and MUC5AC gene expression in cultured hamster tracheal surface epithelial (HTSE) cells. Confluent HTSE cells were metabolically radiolabeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of GYGT to assess the effect on 3H-mucin release. Possible cytotoxicity of the agent was assessed by measuring lactate dehydrogenase (LDH) release. Total elution profiles of control spent media and treatment sample through Sepharose CL-4B column were analysed and effect of GYGT on MUC5AC gene expression in cultured HTSE cells were investigated. GYGT did not affect mucin release from cultured HTSE cells. GYGT did not show significant cytotoxicity. GYGT also did not affect the secretion of the other releasable glycoproteins with less molecular weight than mucin. GYGT increased the expression level of MUC5AC gene. We suggest that the effect of GYGT with their components should be further investigated through ongoing research.