Firmiana kerrii (Craib) Kosterm. (Malvaceae) was previously known from Thailand and Myanmar. It was newly found growing in rocky crannies of limestone hilltops in Mengla County, Xishuangbanna, Yunnan Province, China. Vouchers were deposited at the Herbarium of Xishuangbanna Tropical Botanical Garden (HITBC). A key to the nine species of Firmiana currently known from China is provided.