Abstract: Ungeremine (Ⅱ, AT-1840), an alkaloid from Ungernia minor, was partially synthesized from lycorine. It was shown to possess marked inhibitory action against EAC, P-388, L-1210, Lewis lung carcinoma and Yoshida ascites sarcoma. Some related compounds (Ⅳ～ⅩⅣ) were prepared and screened on EAC in mice to study the SAR. It seems that the presence of phenolic betaine in the molecule of Ⅱ bears some relationship to its antitumour acitivity. From this point of view, 9-demethylberberine and 9-demethytpalmatine (ⅫⅠ and ⅩⅣ), two betaine type compounds, were thus prepared from antitumour inactive berberine and palmatine. The screening results supported the above betaine hypothesis.Ungeremine had been tried on 464 patients with various types of advanced neoplastic diseases. Preliminary data showed that it could improve the general conditions and relieve pain. In 15.7% cases the tumour mass was reduced markedly to less than half of their original volumes. No serious side effect was observed.