A new bamboo species, Bambusa rushunii, from Yangjiang City, Guangdong Province, China, is described and illustrated in this paper. The new species resembles B. gibba and B. dissimulator in having branchlets specialised into weak thorns at the lower nodes of culms, but can be easily distinguished from the latter two by having one or two extremely shortened internodes at the culm base, glabrous internode, culm leaf sheath being dark brown strigose on the central part and with a nearly truncate or slightly obliquely truncate apex, relatively high culm leaf ligule, culm leaf blade base not narrowed, extending outwards and contiguous with auricles and the glabrous foliage leaf with a ciliate ligule margin.