A new alkaloid, paradoxonine, and its enol tautomer, paradoxenoline, in addition to a new cembranoid diterpene, paradoxenoic acid, were isolated from the chloroformic fraction of the methanolic extract of Cleome paradoxa B.Br. The structures of the isolated compounds were established based on their spectral data, including MS, (HNMR)-H-1, (CNMR)-C-13, COSY, HMBC and HMQC. This is the first report on the isolation of alkaloids from the family Cleomaceae.