Objective To observe the effect of Dougen Guanshitong Oral Liquid[oral liquid of Dougen（Radix et Rhizoma Sophorae Tonkinensis）for esophageal cancer]on apoptosis and immune evasion in rats with esophageal cancer and discuss its mechanism based on molecular biology.Methods Fifteen health Wistar rats were selected into the control group.The esophageal cancer model was established by abdominal subcutaneous injection of methyl-n-amylnitrosamine（5mg/kg）.The model rats were randomized into the model group

large-dose group

middle-dose group

small-dose group and tegafur group

with 15in each.The small-dose group

middle-dose group and large-dose group were given 5g/kg

10g/kg and 15g/kg of Dougen Guanshitong Oral Liquid respectively.The control group and model group were given normal saline of equal amount.The tegafur group was given 20mg/kg of tegafur tablet.Administration began at the 24th after model establishment through gastric feeding

once a day

4weeks in all.Twenty-four hours after the last administration

the tumors were removed.The apoptosis was detected by terminal in situ nick end labeling.The immunohistochemistry method was used to detect the expression of Fas and FasL protein.Results Comparing with the control group and model group

the apoptotic index in the large-dose group

middle-dose group

small-dose group and tegafur group was statistically different（P<0.05）.The effect in the large-dose group was significantly superior to those in the tegafur group and small-dose group（P<0.05）.Comparing with the control group

the positive rate of Fas expression in the model group was significantly decreased

but the positive rate of FasL expression was significantly increased（P<0.05or P<0.01）.The positive rate of Fas expression in all the treatment groups was significantly higher than that in the model group（P<0.05）.The positive rate of Fas expression in the large-dose group was significantly higher than those in the tegafur group and small-dose group（P<0.05）.Comparing with the model group

the positive rate of FasL expression in the large-dose group

middle-dose group and small-dose group was significantly decreased（P<0.05or P<0.01）.Conclusion Dougen Guanshitong Oral Liquid could promote the apoptosis of esophageal cancer in a dose-effect manner and its mechanism maybe relevant to increasing Fas expression and decreasing FasL expression.The effect of lage-dose of Dougen Guanshitong Oral Liquid is superior to that of tegafur tablet.