Abstract: According to traditional hypothesis that contradiction between economy development and land protection is increasingly intense, a new hypothesis that the relationship between economic growth and cultivated land changing can be expressed as Logistic curve based on the analysis of change of cultivated land at home and abroad. And then an empirical study was carried out using the national data. Results showed that during the period when the economic growth at abroad transformed from the primary stage to advanced stage in industrialization and urbanization process, the intensity of demand for cultivated land occupied by construction firstly increased and then decreased, which was similar to the Logistic curve. Comparison of different stages in China indicated that per capital economic growth and cultivated land changes had a consistent wave from 1998 to 2003, but then had an inconsistent wave after 2003. Empirical results showed that the relationship between economic growth and cultivated land changing in most provinces could pass the F test, and demonstrate the hypothesis at provincial level between 1988 and 2008 except for 8 provinces. The year 2002 with per capital GDP of 8759.2 Yuan was an inflection point at which the cultivated land changed from accelerated reduction to decelerated reduction. The total cultivated land amounts should not be less than 1.217×106 km2 after 2009. The inflection points and the limit of cultivated land scales had big differences in different regions. The research provides a scientific basis and direct reference for cultivated land protection and public policy adjustments in China.