Climate change is today a hotly debated issue in the world. China is the biggest country in the world in terms of population and agriculture. How exactly to scientifically cope with climate change, draw on the advantages and avoid disadvantages of climate change, and seize strategic opportunity in climate change has been a critical project for revival of China. In this paper, we analyzed and explained the natural and anthropogenic factors of climate change on geological and history and modern time scales. Climate change has had alternate cooling and warming cycles and was currently in the mind warming cycle of quaternary glaciation. It was also suggested to redirect climate change research to include mutual effects from the solar system to the lithosphere, atmosphere, hydrosphere and biosphere. Comparison of changes in economy, society, agriculture and climate showed that Chinas total grain yield increased in recent nine years. This was especially the case for grain production in the Northwest China, which benefited remarkably from warming climate change. It was thus suggested that China seized strategic opportunity in climate change. Because food supply and demand in China was currently in meager balance, China has depended on heavens for food. In spite of the fact that the north is dry with worsening water shorting and sensitive to climate change, more food has been transferred from north to south China. It was therefore suggested that the Chinese government set up projects for studying climate change, water resources security and food security in the north China. The study laid the theoretical basis and technical support for ensuring food security in China.