Abstract:Bryum petelotii Thér. et Henr., a moss species found in Yunnan Province and Guizhou Province in our recently research, was firstly recorded in Mainland China. A description of this species, as well as its taxonomic features and distributions, was presented in this paper. Meanwhile, the comparison among B.petelotii and its related species, Bryum argenteum and Brachymenium exile, was also conducted. Based on literature and evidences from specimens examination, the authors discussed two standpoints on the systematic and evolutional positions supported by H.Ochi and B.C. Tan on B.petelotii. The opinion that B.petelotii belongs to Bryum Hedw. was supported in the paper. The voucher specimens were deposited in the herbarium of Hebei Normal University (HBNU).