Abstract: Abstract: To protect cultivated land earnestly and realize its sustainable utilization, this paper took Bayan county as a study area, dividing it into five cultivated land zones: a plains cultivated land area in the northwest area (region Ⅰ), a plains of diffuse hillock gentle slope cultivated land area in the central area (region Ⅱ), a low mountain slope cultivated land area in the east area (region Ⅲ), a plains cultivated land area in the south area (region IV), and an alluvial plain cultivated land area in the south (region V). From the system point of view, taking a driving factors analysis, which impacts on the cultivated land use system security from the natural, economic, social, and ecological perspectives as the breakthrough, by employing "3S" technology, the study used the factor analysis and weighted comprehensive evaluation methods to calculate security value, and the Kriging interpolation method to divide it into five levels: level Ⅰ (safest), level Ⅱ (safer), level Ⅲ (basic safety), level Ⅳ (critical safety), and level Ⅴ(unsafe), and used the spatial analysis function of raster data to analyze security pattern changes and the spatial evolution of the cultivated land use system during the years 1991―2009 in the study area. The results showed that: in 1991 and 2009, the proportion of each of the security levels in the study area gave priority to level Ⅰ, Ⅱ, Ⅲ, and for level Ⅴ it was low, but from the changing trend of 1991―2009, level Ⅰand Ⅱ showed a decreasing trend, levels Ⅲ, Ⅳ, Ⅴ were an increasing trend, and the security degree of the cultivated land use system was reducing; For the spatial distribution, the security levels of the cultivated land use system were showed imbalance in 1991 and 2009, the northwest was high, the southeast was low, and this trend was higher in 2009 than in 1991. The spatial distribution pattern in each security level showed significantly differences in different cultivated land zones, security level Ⅰ, Ⅱ concentrated in region Ⅰ, Ⅱ and Ⅲ, level IV and V were mainly distributed in region IV and region V, level I as the highest safety rating were mostly in region Ⅱ. The security pattern spatial evolution characteristics were obvious during the past 20 years (1991―2009), and level Ⅰ was focused on the performance of transfers to region Ⅰ, the changes of level Ⅱ were more dispersed, the distribution ratio was decreased in region Ⅰand Ⅳ, and increased in the other three regions, level Ⅲ was transferred from region IV to region Ⅴ, level Ⅳ was spread around the original region, and level V was transferred from the region V to region IV. In order to guarantee the cultivated land use system security of the study area, what was needed was to optimize the land utilization structure, change the traditional mode of agricultural production, strict control of non-agricultural occupation farmland, and exploitation of the reserve resources of the cultivated land reasonably should be used.