Abstract: Food security is an extremely important factor which affects the regional and national socio-economic stability and development. In the context of continuing reduction of cultivated area, the improvement of land productivity is a long term task for China's grain security, and that requires scientific understanding the spatio-temporal differences of land productivity and their influencing mechanism. This paper chooses Hebei Province as the study area which is one of the major grain producing areas, and 136 counties (cities) as the basic spatial units in the province, presents and analyzes spatial differences of land productivity, and then identifies the main influencing factors by using the methods of partial correlation analysis and principal component analysis. The results show that the current regional spatial difference of land productivity is not affected by a single factor, but is the result of several factors influencing together including factors such as terrain and production inputs, and the dominant factor is significantly different in regions at different levels. This is the scientific basis for improving land productivity in different regions.

Key words: Hebei Province, influencing factors, land productivity, spatial difference