Abstract: Grass residues and decomposition of nitrogen and phosphorus in grassing orchards were studied by using the harvest quadrat method. The residues of the 4 grasses, Chamaecrista rotundifolia,Paspalum natatum, Paspalum wetsfeteinii and Borreria latisolia, were 406.00, 1 582.28, 1 542.62 and 658.07 g, respectively, accounting for 33.8%, 76.1%, 59.4%, and 100.0% of the total, respectively. The half-decomposition time of the grass residues was 5 months for P. natatum, C. rotundifolia and B.latisolia, while 6 months for P.wetsfeteini. The nitrogen storage of the annual losses of the 4 grass residues were 90.86%, 67.76%, 88.45% and 88.33%, respectively, which equated the annual losses of orchard nitrogen of 81.16, 119.02, 219.68 and 58.71 kg穐m-2, respectively. These were far less than 864 kg穐m-2.The phosphorus storage of the annual losses of the 4 grass residues were 84.46%, 80.32%, 90.90% and 87.22%, respectively, which equated the annual losses of orchard phosphorus of 167.69, 534.96, 604.49 and 343.22 kg穐m-2, respectively. These were less than the amount of adsorbable phosphorus in the cultivated soil.