This experiment was carried out to investigate the effect of the mulching of hairy vetch and pig manure on the growth, yield and crude protein contents of the mulching of hairy vetch and application of animal slurry were treated and investigated in $2000{sim}2002$. At the first year of cultivation, there were no differences among the treatments in plant height, but second year the growth of plants increased and continued over long times as the hairy vetch mulched and fertilized. The length and diameter of plant root were increased in the plot of hairy vetch mulching and the application of animal slurry. At first year of cultivation, no clear difference was found for among the treatments on dry weight and dry matter ratio in roots. At second year of cultivation, they were increased at in the plot of mulching and fertilizer treatment. The appearances of weeds in the field on Astragalus membranaces were much lower on the plots of live-mulching of hairy vetch than those on the control. The yield of root was 255kg highest in the plot of mulching and animal slurry application of 2-year-old roots. The root yield of Astragalus membranaces was increased about $8{sim}10%$ compared to that with control, due to supply of nutrients. During the cultivation times, organic matters and N contents in soil increased by the mulching of hairy vetch and the application of animal slurry. The concentration of K, Ca concentration in soil showed a tendency to increase.