12social factors,including population,GDP,agricultural mechanization level and urbanizationrate,were selected based on statistic data from 1996to 2009in Guiyang City.The change trend of arableland area in the past 14years and its factors were studied by using correlation analysis and principal component analysis with the aid of SPSS.Results showed that the general trend of arable land area presented a reduction in the study period,and the change of per capita arable land was consistent with that of total arableland quantity.By principal component analysis,the driving factors for the change of arable land area in GuiyangCity were found to be the economic development,population increasement and advanced agricultural technology.Finally,the measures for arable land protection were proposed to make the arable land resources used safelyand sustainably.