To study changes of land use status and vegetation coverage pre and post returning farmland to forest, the TM remote sensing images were interpreted, revealing the practical effectiveness for ecological construction project of Wuqi County, Shaanxi Province by returning farmland to forestry. Based on the air temperature and soil temperature 37year data at 6 meteorological stations surrounding Wuqi County, the effects of the land cover change on temperature in this area have been analyzed. The results showed that Wuqi County layout appears gradually, and has become increasingly clear with the implementation of the project of returning farmland to forest. Meanwhile, the vegetation coverage increases significantly, the high vegetation coverage area is increasing year by year, the low vegetation coverage area is just decreasing, and the vegetation restoration is significantly better than the surrounding area. Compared with 1997, the 75.15% of arable land is no longer farmed by 2007, the withdrawal of the main arable land turns into grassland, woodland and orchards; and the vegetation coverage has increased significantly, from 37.06% in 1997 to 80.60% in 2007. There has an impact on the air temperature and soil temperature after vegetation cover changes, warming trend is declining, the impact of the summer is greater than in winter, and the night time than during the day.