Abstract: Hyoscyamine, scopolamine, anisodamine, anisodine are important tropane alkaloidsbecause of their therapeutic value and pharmacological actions. In recent years, thelatter two new tropane alkaloids have also been proved to affect the central or peripheral nerve system. This discovery has prompted further investigation into solanaceous plants with the hope of finding additional sources with higher content of the sealkaloids. The present paper studied the general pattern of distribution in the Chinesesolanaceous plants, of the above mentioned four tropane alkaloids and a non-tropanealkaloid, bellaradine, which may be biogenetically related to the tropane alkaloids. The variation of these alkaloids within a certain population belonging to Scopoliatangutica was studied as well. By means of TLC, 91 samples representing 19 genera and 54 species of the Chinese solanaceous plants were examined for the presence of hyoscyamine, scopolamine, anisodamine, anisodine and bellaradine. The results (Tab. 1) indicated thatthere is a high incidence of occurrence of such alkaloids in Trib. Solaneae, Subtrib.Hyoscyaminae, Subtrib. Mandragorinae and Trib. Datureae, but a notable absence in Trib. Nicandreae, Trib. Solaneae-Subtrib. Lyciinae, Subtrib. Solaninae and Trib. Cestreae (sensu Wettstein). The results pointed out that certain high-incidence so-lanaceous catagories may prove profitable for searching new sources of tropane alkaloids in the future. The hyoscyamine and anisodamine contents in Scopolia tangutica, Przewalskiashebbearei, P. tangutica, Physochlaina physaloides and Physochlaina infundibulumwere determined (Tab. 2). It was found that the roots of Przewalskia shebbeareiand P. tangutica showed a high content of hyoscyamine and anisodamine, amountingto 1.03%–1.65% and 0.12%–0.37%, respectively, in the former plant, and to 1.02% and0.11%–0.38%, respectively, in the latter. Therefore, Przewalskia shebbearei and P.tangutica would be noteworthy as new sources for these two alkaloids. In order to study the variation of chemical ingredients within a population of Scopolia tangutica, we selected 161 individuals at random to detect the presence of these five alkaloids (Tab. 3). The proportions of positive and negative results were: hyoscyamine 112:49, scopolamine 64:97, anisodamine 154:7, anisodine 31:130, bellaradine 135:26. These data revealed that the presence or absence of the five alkaloidsin a given population are not invariant. Furthermore, the alkaloid contents of hyoscyamine and anisodamine are also variable according to different localities (Tab. 4). The results may be of value to chemotaxonomy or systematics of Solanaceae.