Abstract: One of the key factors for narrow-band k-distribution model is integral scheme, for studying of the impact of integral scheme on narrow-band k-distribution model, five high-accuracy Gaussian integral schemes were studied. The narrow-band average transmissivity data of CO2 for four different conditions were calculated by narrow-band k-distribution of Gauss-Lobatto 7, and the comparison results were in good agreement with those of testing ones. In addition, Four new integral schemes, Gauss-Lobatto 5, Gauss-Lobatto 4, Gauss-Legendre 4 and Gauss-Legendre 2, were used to calculate four cases of CO2, and the comparsions of the results calculated by the five integral schemes with the line by line ones were discussed. The results indicate that the accuracy of Gauss-Lobatto 7 is the highest, next are Gauss-Lobatto 5 and Gauss-Legendre 4, that is higher than Gauss-Legendre 5. Obviously, for the same scheme, the more the number of integral point, the higher the calculation precision and the longer the calculation time, but for two different schemes, Gauss-Legendre is better than Gauss-Lobatto. Considered comprehensively, Gauss-Legendre 4 is better than others.