Objective.To investigate the serum sE-cadherin level in patients with endometriosis and the alterations of that level in healthy control during the menstrual cycle.Methods.Thirty-two patients with endometriosis and 30healthy women were tested for serum sE-cadherin levels by enzyme-linked immunosorb ent assay.Results.The serum sE-cadherin levels in healthy control did not vary throughout t he menstrual cycle

which were lower than those in patients with endometriosis.Conclusions.E-cadherin might be involved in endometrial shedding during menstruati on in endometriosis pa-tients.The serum sE-cadherin assay might be helpful as a serum marker for the diagnosis and management of endometriosis.