Objective To observe the effect and explore the mechanism of Xiaozheng Decoction （Decoction for dissolving masses）

a decoction based on the principle of invigorating blood circulation

removing stasis

reinforcing the kidney

and melting phlegm on endometriosis.Methods Totally 80 patients with endometriosis in the syndrome of blood stasis

kidney deficiency

and phlegm retention were randomized into a treatment group （46 cases

treated with Xiaozheng Decoction） and a control group （34 cases

treated with Gestrinone Tablet）. Before and after treatment

the changes in the clinical symptoms and signs

syndrome manifestations

blood rheo- logy

serum CA125

and the hemodynamic indices of uterine arteries were observed.Results The total effective rate of both groups in the clinical effect and syndrome manifestations were not significantly different （P>0.05）. In the improvement of irregular menstruation

lumbosacral discomfort and morbid leucorrhea

the effect of the treatment group was significantly superior to that of the control group （P<0.05）. After treatment

the pelvic masses in both groups were significantly decreased in size （P<0.01）

without significant difference between the groups. The changes in the blood rheological indices of the two groups were significantly different （P<0.05）. The serum CA125 of both groups was decreased （P<0.05） after treatment

without difference between the two groups （P>0.05）. The hemodynamic indices of uterine arteries in the treatment group was significantly improved after treatment （P<0.05）.Conclusion Xiaozheng Decoction is effective in regulating the blood rheology and hemodynamics of endometriosis patients. The effect may be achieved by improving the pelvic blood circulation through correcting its stasis state.