This article uses Grey Markov forecasting method in Chongqing during the “twelfth five-year” natural gas demand forecasting. Put forward the improved method based on GM (1, 1) model, the fitting precision and prediction precision are greatly improved, good results were obtained. Predicted results show that with the rapid development of Chongqing economy and requirement of low-carbon economy development, the “twelfth five-year” period of Chongqing natural gas demand will into rapid growth trend, by the year 2015 will reach more than 95.19×108 m3. Analysis of supply and demand situation in Chongqing, and put forward to solve the problem of natural gas supply and demand gap.