Based on analyzing the theory of the Optimum Band Combination,Principal Component Analysis(PCA) and NDISI,this paper presents an improved method,i.e.,experimental layer stack,to extract impervious surface of Taiyuan city,Shanxi Province,from Landsat TM image.Both unsupervised and supervised classification methods were used to classify the original multi-band image,PCA image,NDISI and experimental band combination images.The accuracies of the classification were assessed using 256 sampling points randomly se...