Based on the data obtained in artificialRobinla pseudoacaciaandCaraganakor shinskiiwoodlands of Ya'an City

Ansai County and Wuqi County on the hilly-gulled area of the L oess Plateau

soil anti-erodibility of woodlands was studied by choosing natural restoration lands and slope croplands as controls and comparing the 5 anti-erodibility indexes(>0.25 mm water-stable aggregates

>0.5 mm water-stable aggregates

mean weight diameter

aggregation status

and degree of aggregation).By comparative analysis of t he 5 indexes

soil anti-erodibility of artificial woodlands is much better than slope croplands

but not better than natural restoration lands.This is more significant in Ansai and Wuqi.Soil anti-erodibility increases with increasing woodland age and then tends to besteady.All the plots in the three areas can be clustered into three kinds based on the 5 indexes and the same results obtained as the above comparative analysis.It is suggested that natural vegetation restoration without disturbance could be the more adaptive type of vegetation restoration and the bett er measure for soil erosion control in the hilly-gullied region of the Loess Plateau.