This survey was conducted at 26 locations along the Southern Cross-Island Highway in the Guanshan area and the New Central Cross-Island Highway in the Dongpu area. 1,694 bryophyta specimens were collected, 312 of which were identified (177 species, 182 taxa). 161 species were newly recorded in the study areas, 17 of which were recorded for the first time in Taiwan. 5 were new taxa, and 4 were rare species. A comparison of the distribution of bryophyta near the 143rd K of the Southern Cross-Island Highway and the forest area showed that the road area (road + gutter + earth wall) had 34 taxa, the upward and downwards slopes in the forest area had 69 taxa, while the two areas only had 14 taxa in common. This shows that after original forest area was replaced by roads, the species composition of bryophyta changed almost completely. The side effect of such a change in species composition can explained the change of the stability of the ecosystem of the Guanshan area.