Objective:To clarify the basis of total mesorectal excision by studying the morphology of the mesorectum. Methods:Twenty-four pelvises (12 male,12 female) harvested from embalmed cadavers were studied by dissectiodn. Results:There were two different fascial envelopes around the perirectal fat:a posterolateral envelope made up of the visceral pelvic fascia and an anterior membrane made up of the Denonovilliers fascia.Denonvilliers’ fascia couldn’t be regarded as anterior part of mesorectum. Conclusion:The improved prognosis achieved by total mesorectal excision lies in the excision of rectal compartment en bloc.