Abstract: The present paper is a revision of the taxonomy of the genus Sophora Linn. of the world. The history of the taxonomy of this genus is reviewed, and the morphological characters of those genera, in dispute in the past, such as Edwardsia and the Goebelia now incorporated into the genus Sophora are discussed. Opinions on some species to be included in this genus together with the previous taxonomical systems are evaluated. The morphological characters of various organs of the plants in this genus are critically analyzed in detail and their taxonomic significance is assessed. The author considers that the characters of the legume structure and their modes of dehiscence are of primary significance in the taxonomy and phylogeny of this genus. The new taxonomic system of the genus Sophora Linn. proposed by the author is based chiefly on the characters of legume structure, their different modes of dehiscence and other morphological characters. The proposed system divides the genus Sophora Linn. into two subgenera, seven sections and nineteen series. Subgenus Sophora. Legume consists of three layers of imcomplete pericarp (mesocarp degenerated into two narrow strips), different modes of dehiscence on maturity, and flowers ebractiolate. According to the different modes of dehiscence of legume, the subgenus is subdivided into three sections. Section Disamaea Lindl. Mature legume dehiscing typically into two valves. This section consists of two series and five species. Section Pseudosophora DC. Legume dehisced into two valves along two sutures with apparent torn lines on the surfaces of two valves. This section includes three series and six species. Section Sophora. Legume has a part of the epicarp (including mesocarp and the two sutures) dehiscing along the torn linesk and the endocarp (including a part of the epicarp) dehiscing along two sutures, thus spliting cross wise into four valves. This section includes nine series, thirty one species, twelve varieties, and one forma. Subgenus Styphnolobium (Schott) Tsoong. Legume consists three complete layers of fleshy or woody pericarp, indehiscing upon maturity, and flowers frequently. According to the nature of the various layers of pericarp, this subgenus is subdivided into following sections:Section Raphanocarpus Tsoong. Epicarp is membranous, mesocarp has apparent nerved reticulation, endocarp fleshy, and seeds overlapping. This section has one serices and one species only. Section Arizoniatae Tsoong. Legume is slightly distorted, epicarp membranous, mesocarp fleshy, and endocarp elastic. This section has only one series, two species and one variety. Section Agastianus (Rafin.) Tsoong. Legume epicarp and mesocarp apparently lignified, and endocarp is nearly membranous. This section has only one series and one species. Section Styphnolobium (Schott) Tsoong. Legume epicarp is membranous, mesocarp and endocarp are fleshy, and leaflets with subulate stipel. This section includes two series, two species, four varieties and five formae. Keys to the taxonomical system and species in each series are given. In these keys are included all the species observed by the author, their taxonomical positions can be inferred by descriptions. Species of uncertain taxonomical positions are duely discussed and opinions as to their proper treatment are expressed. A few species, with their specimens unavailable to the author and their taxonomical positions cannot be inferred as judged by the original records, are temporarily put aside at the end of the paper as species of unknown systematical position, until their type specimens are examinedin the future or decisions are made by other taxonomists.