A new species of Lespedeza (Fabaceae) from Jiangxi Province, China is here described as Lespedeza jiangxiensis. The new species is morphologically similar to L. inschanica, but differs on the obovate leaflets with densely adpressed-pubescence adaxially and abaxially, shorter floral peduncles (0.5–1 mm long), shorter calyces (2.9–3.8 mm long), and white to yellowish-white keel-petal apices. In contrast, L. inschanica is characterized by oblong leaflets that are glabrous adaxially, longer floral peduncles (3–10 mm long), longer calyces (5–6 mm long), and light purple keel-petal apices. A phylogenetic analysis based on DNA sequences of plastid rpL32-trnL and trnL-F intergenic spacers identified L. pilosa as the closest relative of L. jiangxiensis. Interestingly, however, L. pilosa is remarkably different morphologically from L. jiangxiensis. Pollen grains of L. jiangxiensis are similar to those of L. chinensis, L. inschanica, and L. pilosa in size, shape, and germination organ type, but clearly different in exine sculpture.