Abstract： Objective To explore the changes of peripheral blood lymphocyte subsets in patients with acute hydrogen chloride gas poisoning.Methods When the patients were admitted or on the secondary day,the percentages of total T-cell lymphocyte subsets (CD3+CD19-),CD4+ T cells (CD3+CD4+),CD8+T cells (CD3+CD8+),B cells (CD3-CD19+) and NK cells (CD3-CD16+CD56+),and the ration of CD4+/CD8+in 37 cases with acute hydrogen chloride gas poisoning and 49 healthy controls were detected with flow cytometer.Results The total T-cell percentage and total CD4+T cell percentage in 37 cases were significantly lower than those in 47 controls (P＜0.05).The percentages of NK cells and B lymphocytes in 37 cases significantly increased,as compared with controls (P＜0.05).The ration of CD4+/CD8+ in 37 cases significantly decreased,as compared with controls (P＜0.05).Conclusion The lymphocyte subsets in the patients with acute hydrogen chloride gas poisoning changed,which could influence the immune function of patients.