Based on data available from soil water conservation, soil monitoring and agricultural environment protection, analysis was done of the effects of human activities on cultivated land in Guangdong Province. The results indicate that in the past decade, with the steady increase in agricultural input, in most of the cultivated land in Guangdong soil fertility shows a rising trend, nutrient composition of the fertilizer tends to be more reasonable and yield of the agricultural crops keep on rising. However, the problem of human activities affecting quality of the cultivated land is also prominent, mainly in the form of soil erosion, regional over-application of fertilizers and degradation of the land due to environment pollution. In order to improve quality of the cultivated land,some concrete measures are brought forth in the paper.