Road erosion is one of soil erosion types in regions. To grasp the mechanism of road erosion

runoff plots were used to make observations

and results show that :(1)Characters of rains in study area: the rainfall and rain intensity are mainly 5~10 mm and <5 mm/h respectively in most rain events

and they brought 52.89 mm and 61.31 mm rainfall respectively

which getting to 56.72%

65.76% of whole rainfall respectively.(2)There are well linear relationships between the product of rainfall and rain intensity

sediment concentration and runoff depth

and their correlation coefficient are 0.657 6 and 0.798 2 respectively. These are well accordance to USLE

so the integration of rainfall and rainfall intensity can be an important factor to predict soil losses from road embankment slope. (3) Natural logarithms of sediment concentration and that of runoff depth are well linear (correlation coefficient R=0.863 3)

sediment concentration is increased with runoff depth increasing.Mean runoff coefficients is 0.29

of which show that there are large infiltration capacity in the embankment slope.