Objective: To investigate the effect and clinical significance of Xuebijing injection on periph-eral T-lymphocyte subpopulations in patients with severe trauma.Methods: Thirty-three patients with severe trauma were randomly divided into a control group (n=16) and a treatment group (n= 17).The patients of two groups were all treated conventionally, and the only difference was that Xuebijing injection was given to patients of the treatment group.The CD_4~+ and CD_8~+ subpopulations of T-lympho-cyte in the peripheral blood were detected respectively on admission, 3rd and 5th days after trauma by double anti-body labeling and flow cytometry.Results: The CD_4~+ T-lymphocytes and CD_4~+/CD_8~+ ra-tio of peripheral blood in patients with severe trauma de-creased markedly on the 3rd and 5th days after trauma.Furthermore, compared with control group, the peripheral CD_4~+ T-lymphocytes and CD_4~+/CD_8~+ ratio of treatment group renewed obviously on the 5th day after trauma, and showed statistical differences (P