Abstract: This paper is a continuation of “Chemotaxonomy of Cynanchum and Its Allied Genera with Notes on the Generic Characteristics of Vincetoxicum”, published in Acta Botanica Yunnanica (11: 41-50, 1989). There are other three sections of Cynanchum in “Flora Reipublicae Popularis Sinicae” (Vol. 63), which were considered as separate genera by some authors. These sections are Cynanchum Sect. Rhodostegiella, Sect. Seutera and Sect. Cyathella, also of a single corona. They were not given generic rank as chemical data of Sect. Rhodostegiella were inavailable. It is for this reason that we have studied the chemical constituents of this section. A very marvellous result was obtained. No C₂₁ steroidal compounds but flavonols were identified from the section Rhodostegiella. Some flavones were isolated from Hoya bella of Asclepiadaceae (Bass et al., 1979), but no report has been given from Cynanchum and the tribe Asclepiadeae up to now. The family Asclepiadaceae mainly contains C21 steroids, but some genera contain cardenolides or terpenoids, and only a few genera, such as Cryptolepis and Tylophora, have alkaloids. The genus Cynanchum sensu Tsiang et P. T. Li, like most members of Asclepiadaceae, has C₂₁ steroids except the section Rhodostegiella. Flavonols, therefore, may be the characteristic of the section. Considering the corona characteristics and geographical distribution, we suggest that the section Rhodostegiella be given generic rank. Because of the separation of Vincetoxicum Wolf and Rhodostegiella (Pobed.) C. Y. Wu et D. Z. Li from Cynanchum sensu Tsiang et P.T. Li, the rank of the sections Seutera and Cyathella should be reconsidered. Obviously, the problem of evolution of the sections of Cynanchum sensu Tsiang et P. T. Li is complicated. The corona, chemical constituents, habit, root-type are not congruent with one another in evolution. The authors support the establishment of the genera Seutera and Cyathella by Reichenbach (1828) and Decne (1838) respectively. Taxonomic treatments, including a new status, Rhodostegiella (Pobed.) C.Y. Wu et D. Z. Li, and 12 new combinations, are given.Key words Cynanchum Linn.; Rhodostegiella (Pobed.) C. Y. Wu et D. Z. Li; Seutera Reichb.; Cyathella Decne.; Flavonols; Chemotaxonomy; New combination