There are close linkages between soil loss degree and soil disturbance degree by human. So it is a key problem to know that how human activity affects soil loss. In this paper

to analyse the correlation of 137Cs loss degree with hillslopes’ cultivated histories

the concentrations of 137Cs on different kinds of loessial hillslopes with different cultivated histories

abandoned ages and different patterns of reforestation are studied. The result shows that there is a linear relationship among 137Cs areal concentrations

cultivation ages and slope gradients. The regressive equation is as follows: X= 2356.79 - 22.77 t - 35.53 S . Variant coefficient of 137Cs areal concentration is 80.11% among hillslopes with different abandonment ages. It is also deduced that 137Cs areal concentration is affected primarily by abandon-ment ages of hillslopes. The 137Cs loss rates of hillslopes with different vegetation restoration manners show signifi-cant differences

as a whole

autogenic restoration < constructing ecological forest < constructing economic forest in Yangou watershed. The history of land utilization is therefore considered to be the main cause that affects 137Cs area concentrations on hillslopes.