AIM: To explore the therapeutic effects and the mechanism of Chinese herbs on Antiphospholipid Syndrome (APS) by observing the effects of Salvia miltiorrhiza bunge Injection (SMBI) on anticardiolipin antibody (aCL) induced by β 2 glycoproteinⅠ(β 2 GPⅠ). METHODS: 60 female mice of 4 wk randomly fell into 6 groups. Group A was treated with small dosage, group B with mid dosage, group with C large dosage, group D with mid dosage without immunization of β 2 GPI, group E was immunized only with β 2 GPI and group F as control. Group A, B, C and D were injected through abdominal cavity with different dosages of SMBI daily and after 14 d, group A, B, C and E were immunized with 150 μg of purified human β 2 GPI in Complete Freund’s adjuvant (CFA) subcutaneously. T cell subsets were grouped by Streptavidin Biotin Complex Technique and the activity of IL 2 was measured by MTT chromatometry. RESULTS: Compared with that in group E, T H/T S ratio was reduced in group A, B and C ( P <0.05 or P <0.01) and no significant differences were found between group D and F ( P >0.05). By linear correlation, the dosage was negatively correlated with T H/T S ratio ( P <0.01). Compared with that in group E, the activity of IL 2 in group B and C decreased significantly ( P <0.01) and by linear correlation, there was a negative correlation between the dosage and the IL 2 activity ( P <0.01). There was no significant difference between group D and F ( P >0.05). There was a positive correlation between T H/T S ratio and IL 2 activity in different dilutions ( P <0.01). CONCLUSION: The suppressive effects of SMBI on aCL induced by β 2 GPI may be realized by reducing the elevated T H/T S ratio and IL 2 activity and SMBI has no effect on normal mice.