Abstract: Based on the fieldwork and quadratic analysis about the relative hight of the terraces of the Wudinghe river and the channel length from the terrace Iocation to the head of the river and the time-lapse remote sensing measuring, this paper shows that the rate of the headward erosion is about 1.5 m ．per year in the loess gullies．The downward erosion rate was 0.37 cm./yr. in Q²₂, and has been being 0.53 cm/yr. since Q³₄ and about 0.2 cm/yr. since 700 yr. B. P. in main channel and 0.18-2cm./yr. in loes hilly-gullied rigion.