Abstract: The gas production process in underground coal gasification is closely related to the temperature distribution in gasification oven and seepage conditions. A mathematical model on underground gasificaton in steep coal seam is established, according to its storage conditions and the feafures of gas production process. The paper also introduces the methods of how to determine the main model parameters, and gets the model values by means of the control volume method, and gives an analysis of the calculation results on the basis of model experiment. From the distribution of temperature field, the calculation values are slightly higher than the real measurement ones. The relative differentiations of all measuring points are by and large within 10%. According to the simulated calculation results, with the increase of the length of the gasification channel, the heating value of the gas increases. However, after the reduction zone, it increases with a smaller margin. The temperature field exerts noticeable effects on the heating value of the gas. Due to the effect of temperature, in high temperature zone, the change gradient of the measured values of the concentration field of the gas compositions is larger than that of calculated ones. On the whole the simulated values are identical with the test ones,which manifests the numerical simulation on the temperature field and concentration field in steep seam is right.