Man-land relationship has become one of the most sensitive problems in agricultural development, and study on land productivity and population supporting capacity opens up an effective way for quantifying regional man-land relationship. In this paper, we discuss present and future environmental capacity status and variation trend in Xiangjiaba reservoir area on village basis with land potential productivity degression method and bearing capacity evaluating model, regarding cultivated land as study object. According to geographic status, land bearing capacity evaluating region is confirmed, covering 23 832.91 ha and involving 21 towns or 174 villages. Coupling analysis of land use and physiognomic characters in the study is conducted with GIS and RS, and then the integrated spatial-attribute database is established. Supported by perennial sun light and temperature data, soil physio-chemical attributes on village scale, cultivated land spatial distribution and main crops (including paddy, wheat and corn) growing period in the reservoir area, the appraising index system of land productivity is set up, synthetical crop productivity of cultivated land on village scale is evaluated with land potential productivity degression model. Taking into consideration comparatively well-off standard of living for local people,including per capita grain and farmland availability,as capacity index of grain to support population, we establish land bearing capacity model based on reservoir construction planning and spatial pattern of land productivity to forecast per village farmland resource potential carrying capacity at present and in the near future(2012), and put forward environmental capacity of the whole study area coincided with local agricultural development. The result shows that multiple-cropping practice compared with other farming methods can gain even greater population supporting capacity; it is more reasonable to study land population supporting capacity based on output of grain rather than on farmland area, however, they should be combined with each other in practice; because the impact of fully implementation of land conversion from farmland to forest and grassland on land carrying capacity is greater than changes of unit area output of grain, hence under the same farming practices, the future land population supporting capacity does not increase but is smaller than the present environmental capacity, presenting an overall decreasing trend inevitably; environmental capacity of reservoir area is inclining to saturation, man-land conflict stands out;and population supporting capacity of cultivated land should be increased to some degree by means of increasing output of grain through expanding sown area of paddy and ameliorating breed.