Objective: Saponin of Achyrathes Bidentata's chemical composition has a role of antifertility. In order to investigate the role of antifertility of Saponin further, monocrystal saponins were isolated from the dry root of wild growing Achyrathes Bidentata and their chemical structures were determined. Methods: The monocrytal saponins were isolated by ethanol abstract method and silica gel low pressure column. Their structures were determined on the basis of chemical and spectral analysis (IR, MS, 1HNMR, ...