Based on the rule of cropping system, potential sown area is used to analyze the response of crop sown area to climate change, and other combined factors as well. Some results are concluded as follows. Actual sown area in China increases slowly, with obvious regional disparities, expanding in Southwest China, Central China, Northeast China and Xinjiang, while reducing in other regions. The maximum of actual sown area is in Central China, and the minimum is in Xinjiang. According to ≥ 10 °C accumulated temperature, the average of non-cultivated areas in China in the period 19862009 decreased by almost 34.33% compared with the period 19611985; single cropping area cut a little bit, while still remained the largest share of about 50%; double cropping area increased the most, and the area of triple cropping followed. The combination of ≥ 10 °C with ≥0°C accumulated temperatures is available to show a slow increase in China potential sown area, with high similarity to actual sown area. On the contrary, other factors as a whole restrain the expansion of sown area slowly.