Based on the panel data of provincial rice production in China from 1985 to 2011, the trend of Chinese provincial grain structure variation and the comparative advantage of rice areas was analyzed by the index of production concentration degree and comparative advantage. The results showed that rice production concentration degree in the middle and lower reaches of Yangtze River was about 48% since 1985. And the degree in the southeast coast fell from 27.21% in 1985 to 17.36% in 2011, while the degree of northeastern area was raised from 3.16% in 1985 to 15.87% in 2011. Comparative advantage analysis showed that the comparative advantage in middle and lower reaches of Yangtze River and southeast coast areas were significant, but northeastern area was not. The three rice production areas should make the best of their own producing advantage to balance our nation’s rice supply and demand, thus ensuring our food security.