Euonymus fangdingianus, a new species from southwestern China and northern Vietnam, is described and illustrated. This species differs from its congeners mainly in having large thick leave blade, abaxial black-punctate blade, impressed and abaxial prominent veins, cauliflorous inflorescences, dark purple flower in 5-merous, and obovoid capsules with angles and grooves. A photograph image and conservation assessment for the new species are provided. In addition, the cauliflory in E. fangdingianus, an unusual flowering pattern in Euonymus, is described preliminarily.