Glycosmis longipetala F. J. Mou ＆ D. X. Zhang is described from Guangxi and Yunnan provinces in southwestern China. The new species is similar to G. cochinchinensis （Lour.） Pierre ex Engl. by its simple leaves, but distinguishable in having long-elliptic or oblanceolate （vs. ovate） leaves, long-ovoid to ellipsoid （vs. ovoid） floral buds, ovaries with many tubercles （vs. smooth） and glabrous （vs. pubescent） stamens. The pollen grains of the new species are 23.9±3.09 （20.8-27.0）×22.0±1.80 （20.4-24.4）μm in size with reticulate exine ornamentation in equatorial area and foveolate in polar area. The chromosome number of the new species is 2n=72.
