ObjectiveA mouse model of ethanol consumption was set up. This model was used to investigate the effect of ethanol-exposed on the serum estrogen level and breast cancer progression in mice. Methods2% ethanol in drinking water was given in the ethanol-exposure group mice (n=15) from 8:00 pm to 8:00 am and then replaced with regular water without ethanol at the remaining 12 hours each day for 3 weeks. Mice in the control group (n=15) were provided with regular drinking water only. The water intake, body weight and blood ethanol concentration (BEC) of the mice were checked. The estrogen level in mice serum was quantified by enzyme-linked immunosorbent assay (ELASA). Results The BEC in mice was much higher than that in control mice and similar to drinking humans. No water intake, body weight differences were found in mice with ethanol exposure or without. The serum estrogen level in ethanol drinking group was much higher than that in the control group.ConclusionA mouse alcohol-exposure model has been successfully established. Ethanol consumption might increase the serum estrogen level in mouse.