| The situation has been serious that the land has degraded in the west of Liaoning province during recent decades. A lot of areas have already become the fragile district of the ecology. The mesoscale(MM5V3-5) model was used to simulate the change of temperature, heat flux by means of changing landuse according to the survey data about the land degradation and renewing in the west of Liaoning, which used data in June,July and August,2001. Choose 120 E,43 ?N as the operation center of the model and use two layers of nested schemes.The resolution ration of the coarse nest is 51km while that of the fine nest is 17km. The number of the grid in the focast area of the coarse nest is 65 ×71 while that of the fine nest is 73 × 82.The results show that the local average temperature and average surface temperature will rise,and both daily difference will rise,too.Average sensible heat flux and its daily difference will also increase while average latent heat flux and its daily difference will reduce after the vegetation degration of some area in the west of Liaoning province; the average temperature will raise 0-0.5℃, average surface temperature will raise 0-1.0℃, average sensible heat flux will increase 5-40w/m2, about 8-55% and average latent heat flux will reduce 5-60w/m2, about 4-48%. The change caused by the vegetation degration of the tempreture and the heat flux in the afternoon is more than that of the average. At about 14:00, the tempreture will raise 0-0.8℃,surface temperature will raise 0.3-2.1℃, sensible heat flux will increase 20-100w/m2 and latent heat flux will reduce 20-140w/m2; the change caused by the vegetation degration of the tempreture and the heat flux in the early moning is less than that of the average. At about 05: 00, the tempreture will raise 0.05-0.3℃,surface temperature will raise 0.1-0.4℃, sensible heat flux will increase 1-6w/m2 and latent heat flux will reduce 2-6w/m2.The local average temperature and average surface temperature will drop, and both daily difference will drop,too.Average sensible heat flux and its daily difference will also reduce while average latent heat flux and its daily difference will increase after the vegetation is renewed partically in the west of Liaoning province; the average temperature will drop 0.05-0.35 ℃, average surface temperature will drop 0.1-0.8℃, average sensible heat flux will reduce 5-25w/m2, about 8-40% and average latent heat flux will increase 5-40w/m2, about 4-35%. The change caused by the vegetation renewed of the tempreture and the heat flux in the afternoon is more than that of the average. At about 14:00, the tempreture will drop 0.1-0.5℃,surface temperature will drop 0.2-1.6℃, sensible heat flux will reduce 10~50w/m and latent heat flux will increase 20-100w/m2; At about 05: 00, the tempreture will drop 0.1-0.4℃,surface temperature will drop 0.1-0.3 C, sensible heat flux will reduce 2-12w/m2 and latent heat flux will increase 3-15w/m2. What shoud bepaid attention to is that there are also some changes of the average tempreture and heat flux in the area where the landuse hasn't been alterd.The baric field and the tempreture field of high latitude will have some changes because of the change in the vegetation states of the landuse. Whether the vegetation degraded or renewed, it can both make the atmospheric pressure over it drop, and the height can reach about 200hPa. This change seems to be more obvious to the east of the area where the landuse has been changed, in the vertical direction the center of the pressure dropping lies at about 850hPa. The degraded vegetation can make the tempreture of it's upside rise and the tempreture beside it drop; the renewed vegetation can make the tempreture of it's upside drop and the tempreture beside it rise.The results of the study show that the affections to the local climate are rather obvious when the vegetation are changed in the west of Liaoning province. Of the several kinds of vegetation change in the west of Liaoning province, the vanish and the resume of the forest...
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