The strength and source of anthropogenic sulfur (S) deposition is an important area of research in both environmental and ecological disciplines. Here S concentration, stable isotope (delta 34S) and photosynthetic pigments analyses were performed on epilithic mosses at Guiyang area (SW China) for investigating the distribution, origin and effect of urban-derived S at the urban-rural scale. Based on the variation of moss S. anthropogenic S was estimated to account for about 52% of total S in urban mosses and 35% in rural mosses within 30 km. The deposition of urban-derived S was biologically determined within 57 km from the urban center, but only 22% (about 24.4 x 10(6) kg-S annually) reached over 30 km, with 78% (about 85.9 x 10(6) kg-S) deposited within 30 km. delta S-34(moss) signatures suggested the major source of anthropogenic S was still from coal combustion, and comparable delta S-34(moss) values along the urban-rural transect suggested the inputs of urban-derived S into rural ecosystems. Unexpectedly, moss photosynthetic pigments did not show a decrease with S deposition, but express higher concentrations in the urban than in the rural. In contrast, correlations between moss photosynthetic pigments, and tissue nitrogen (N) and delta N-15 demonstrated a fertilizing effect of elevated N deposition on moss photosynthesis, which might buffer or offset the negative effect of S deposition on urban mosses. Collective evidences suggest that S% and delta S-34 in epilithic mosses provided useful information for determining anthropogenic S deposition on the urban-rural scale, but moss photosynthetic pigments may not be applicable for reflecting S loading under high N deposition. (C) 2011 Elsevier Ltd. All rights reserved.