Abstract: Objective: To study the effect of Eucommia tea on defecating function in constipated mice. Methods: Kunming mice were randomized into 6 groups: solvent group, model group, positive group and 3 dosages groups. Mice of solvent group and model group were given by gavage with distilled water of 20 m L/kg BW once a day for 8 days, mice of positive group were given by gavage with Maren Wan of 1.0 g/kg BW once a day for 8 days, mice of 3 dosages group were given by gavage with different dosages of Eucommia tea ( 0.4, 0.8, 1.6 g/kg BW) once a day for 8 days.Then the weight of each group of mice was recorded, the time of the first black feces to be excreted and the number of feces within 5 hours were observed, water content of mice feces and ink propelling rates were mensurated, statistical analysis was performed using the SPSS software. Results: There was no obvious effect about experimental dosages of Eucommia tea extrat on Body weight of mice, and the effects of lower, medium and higher dosages of Eucommia tea extrat on the time of the first black feces to be excreted, the number of feces within 5 hours, water content of mice feces and ink propelling rates respectively were no significant ( p > 0.05) , significant ( p < 0.05) and very significant ( p < 0.01) .Conclution: The results demonstrate that Eucommia tea has significantly cathartic effects in mice.