The cosmogenic 7Be is a better tracer in tracing particles movement

and has been applied to study soil erosion. But the study that the cosmogenic 7Be is imbibed and intercepted by the cover materials on the soil surface is relatively less

which leads to a direct impact on the accuracy of the tracing results

the establishment and application of the tracing models. In this paper

the cosmogenic 7Be content of different cover materials on the soil surface was analyzed

the results showed that the withered plant cover contained the highest 7Be activity among the incomplete decomposed and the living plant cover in the end of springtime. For the living plant

the cumulative value of 7Be con- tent increased gradually in their whole life

obviously in the fall. In addition

the 7Be contents in different plant spe- cies were analyzed statistically

the results indicated that different plants contained different 7Be contents and the variation coefficient was about 0.6 among the plants. The trend of the average 7Be content in different plants was the herbage >the half-shrub and shrub>the crop. But compared with other species

the variation coefficient of 7Be in dif- ferent crops changed greatly with about 0.47.