Abstract: A new phenolic dauricine-type alkaloid together with the know dauricine, were iso-lated from the rhizoma of Menispermum dauricum DC cultivated in Xianning district, Hubei province.Dauricine was obtained as the major alkaloid and was confirmed by comparison with authentic sample.The new alkaloid is an unstable white powder. Based on spectrometric analysis (UV, IR, FAB--MSand ¹HNMR) and N-methylation which offered clauricine dimethiodide(Ⅴ), the structure was elucidat-ed as RR, N-desmethyldauricine(Ⅱ), which was isolated for the first time from nature.