Temperature and precipitation are the main climatic factors affecting regional vegetation coverage. With the time lag correlation method

the correlations between the ten days NDVI(TN)and ten days mean temperature(TT)

ten days mean precipitation(TP)as well as the time lag characteristics were analysised based on ten days SPOT VGT-NDVI data

daily air temperature

and precipitation data from 20meteorological stations in Chongqing City and around for the period 1999-2010.The results are summarized as follows: Across the entire study region

both correlations with NDVI existed apparently while air temperature had closer than precipitation

which indicated that the temperature is the limiting factors of NDVI variations across the region;there are significant spatial and temporal variation differences with longger time lag and lower correlations from southeast to northwest;the degree of correlation between NDVI of different vegetation types and air temperature and precipitation is determined by the vegetation's growth characteristics and its water and heat requirement.