We have investigated the alkaloids of three previously unstudied species of Aconitum growing in Mongolia. The epigeal part of Aconitum baikalense Turcz. gathered in the Ara Khangai aimak (province) in the fruit-bearing period yielded by ordinary chloroform extraction 0.3% of alkaloids on the weight of the dry plant. Three bases were isolated by separating the total alkaloids on a column of silica gel with elution by benzene-methanol: (I) with the composition C31H47NO11, mp 200-202°C; (II) with the composition C22H32NO3, mp 197-199°C; and (III) with the composition C22H33NO3, mp 164-166°C. From their spectral characteristics, the results of a comparison by TLC, and mixed melting points, bases (I-III) were identified as aconitine [1], songorine [2], and napelline [3], respectively. The epigeal part of Aconitum volubile Pall. ex Koelle, gathered in the Bayan Khongor aimak in the fruit-bearing period contained 0.6% of alkaloids on the weight of the dry plant. When the alkaloids were chromatographed on a column of silica gel with elution by benzene-methanol, two bases were isolated, and these were identified as aconitine and napelline. From the epigeal part of Aconitum altaicum Steinb., gathered in the Kobdo aimak in the fruit-bearing period was obtained 0.13% of alkaloids on the weight of the dry plant. When the alkaloids were treated with acetone a crystalline mixture was obtained from which napelline was isolated by chromatography on a column of silica gel.