Objective To discuss the effect and functional mechanism of Dihuang Guanshitong Oral Liquid（Oral liquid of Radix Rehmanniae for esophageal cancer） on esophageal cancer model rats after radiotherapy.Methods Twenty Wistar rats were put into a blank group.Another 110 rats were given subcutaneous injection of methyl amyl ammonium nitrate 5mg/kg to establish esophageal cancer models.Except the 20 rats in the esophageal cancer group

the rest of rats were divided into five groups and treated by 60Co radiotherapy for the local area.There were 18 rats in the simple radiotherapy group.The others were divided into Liuwei group [18 rats

Liuwei Dihuang Wan（Bolus of Six Medicines Including Rehmanniae） suspension in the concentration of 0.45g/ml for intragastric feeding after radiotherapy]

Dihuang Guanshitong high-dosage

medium-dosage

and low-dosage groups（18 rats in each group

Dihuang Guanshitong Oral Liquid in the concentration of 1.5g/ml

1.0g/ml

and 0.5g/ml respectively for intragastric feeding 10ml/kg after radiotherapy）.The blank group

esophageal cancer group

and simple radiotherapy group were treated by intragastric feeding with distilled water 10ml/kg for 5 weeks.The morphological changes and the positive rate in the esophageal human telomerase reverse transcriptase（hTERT） of all groups were observed with microscope.Results The nucleus and cytoplasm of the Dihuang Guanshitong high-dosage

medium-dosage

and low-dosage groups and Liuwei group were in the brown-yellow colour in staining

significantly light-coloured than that of the esophageal cancer group.Compared with the esophageal cancer group

the difference in the hTERT positive rate of each medicated group was all statistically significant（P<0.01）.The difference between the Dihuang Guanshitong high-dosage group and simple radiotherapy group was statistically significant（P<0.05）.There was no statistical difference in the comparison among all medicated groups（P>0.05）.Conclusion Possibly

Dihuang Guanshitong Oral Liquid prevents the recurrence of esophageal cancer after radiotherapy through down-regulating the activity of hTERT expression.