Objective: To study the influence of T-suppressor cell activity on habitual abortion (HA) and to observe the regulatory effect of Yangxue Antai Granule (YXATG) on T-suppressor cell and its effect on fetus preservation. Methods: T-suppressor cell activities of 56 pregnant women with H A history were tested with method of short life T-suppressor cell activity (MTT method) during early pregnancy, and were followed-up in middle and late pregna ncy in 20 cases of them. All the 56 patients YXATG treatment. Groups of normal early pregnant, normal non-pregnant women and those non-pregnant but with history of habitual abortion were involv ed in this study as control. Results: T-suppressor cell activity in early pregnancy was lowe r than that of middle and late pregnancy (P