A new moss species, Bryoerythrophyllum pseudomarginatum J. Kou, X.-M. Shao & C. Feng (Pottiaceae), is described and illustrated from Tibet, China. It is most similar to B. hostile, but differs from it by having much larger plants, branched stems, oblonglanceolate to lingulate leaves with broadly acute or round and apiculate apices, leaf margins that are strongly recurved from above leaf base to distal 1/2–1/3 leaf length and distantly and irregularly dentate above, a weakly differentiated, discontinuous border consisting of several weakly papillose, transparent marginal cells in one row, a strong and percurrent costa, and by having thickened transverse walls in basal leaf cells.