AbstractWe investigated ground bryophytes under artificial Pinus tabuliformis forests with four different slope aspects, i.e. NE80°(east facing slope, E), NW85°(west facing slope, W), SE10°(south facing slope, S), and NW20°(north facing slope, N) along the upper reaches of the Minjiang River, in order to explore bryophyte species composition and structural characteristics. Of the 13 bryophyte species occurring in the four artificial forests,only 6, 11, 12 and 7 species occurred in E, W, S , and N forest, respectively. Six moss species, Brachythecium glaciale, Thuidium cymbifolium, Entodon concinnus, Eurhynchium savatieri, Oxystegus cuspidatus,and Porella pinnata existed commonly in all the four forests. The highest frequency for bryophyte occurrence was 100% under W and N forests, and the lowest, under the E and S forests, was 96.7%. According to importance value, the dominant species were Brachythecium glaciale and Thuidium cymbifolium under all four Pinus tabuliformis forests, indicating that they were the most common moss species in the study area. For E, W, S and N forests, ground bryophyte coverage were 5.50%±0.90%, 25.66%±2.76%, 9.03%±1.76% and 7.93%±1.16%, respectively, while hoot density were 480.67±133.65, 2724.80±419.72, 982.00±191.33, 923.47±173.51 shoots/m2, respectively, and average bryophyte thickness were 4.73±0.31, 6.67±0.41, 6.83±0.73, 5.42±0.33 mm, respectively. No statistical differences（P>0.05）in structural parameter were found among E, S and N forests. By comprehensive analysis, it was found that W forest was the best of the four forests in bryophyte composition and synusia structures, indicating that slope aspect is one important environmental factor inducing differences of ground bryophyte composition and synusia structure, and indirectly affecting the survivorshipand growth of bryophytes.