Making full use of the air temperature, precipitation, normalized difference vegetation index (NDVI) data during 2000 to 2012, the variation of climate and vegetation in Horqin sandy land, as well as the response relationship between vegetation and climate factors were analyzed by qualitative and quantitative methods. The results showed that the vegetation in the region deteriorated gradually from east to west, the area of vegetation growth deteriorated accounted for 28.56% of the research area, and the vegetation growth of the remained area showed ameliorated trend. Perennial vegetation grew well with NDVI, while the precipitation increased faintly and the temperature variation trend was not obvious. The vegetation growth was influenced greatly by 2~3 months accumulated precipitation, the temperature of the month and average temperature of 2~3 months. The vegetation growth was promoted by the following factors, including precipitation increment, temperature rising during April to November, the lowest temperature increment in April compared with inter-annual variation of April to August, as well as the highest or the average temperature decrease from June to August. When NDVI was 0.03~0.33, the vegetation growth was influenced obviously by temperature, when NDVI was 0.33~0.43, it was influenced obviously by precipitation, when NDVI was 0.43~0.62, it was influenced by both temperature and precipitation, however, when NDVI was 0.53~0.62, it was inhibited by the rising temperature. NDVI responded to the changes of precipitation or temperature or combined action of precipitation and temperature in different response ranges, which might overlap.