Gas emission would be affected by some nonlinear factors,such as geological structure,thickness and porosity features of coal seam,etc.,and the implication was that it may perform in a chaotic way.Based on chaos theory,the chaotic performance of gas emission was analyzed in detail in this paper.In view of the disadvantages of conventional CC method,an imp roved CC method used in the optimizational selection of time delay and embedding window was presented,which helped to exhibit the chaos features of gas emission in the phase space reconstructed,to predict the gas emission accurately.The analysis of data from gas emission experiment showed that high-precision phase space parameters and the accurate forecasting results of gas emission could be obtained using the improved CC method.Furthermore,the largest Lyapunov exponent deriving from the improved CC method also proved the existence of the chaos performance of gas emission.