Abstract: Effecm of different mulching nn sgtring corn yield and on soil environment in Loess Plateau, Heyang County were studied. The results showed that different mulching could increase the crorn yield significantly. Soil water rnn-tents were increased remarkably except normal plastic film mulching, and the upper soil Layer kept wet far a long time-Mulching could also reduce temperature difference of day and night, kcett soil surface from direct precipita-Lion lash, and maintain better sail structure. Compared with straw mulching, normal plastic film and no mulching, water osmosis plastic film could increase the yield by 6.4%,23.6% and 29.1%,the water use elliciency 21.5, 20.2,17.4 and 16.7 kg·mm^{·hm-2,respectively.Straw mufrhing could remarkably increase soil organic matter and soil fertility. Water asmvxis plastic film had the same effect of inereasistg temperature as normal plastic film. While air temperatum was more than 35℃,water osmosis pla.Rtir fi3m had the fuactinn of reduring extreme temperawre, but long term mulching would promote exctssine mincralixation of soil organic ni-trogen and leaching of NO₃-N.}