Abstract: With the principle component analysis (PCA), this paper preserts a new approach to effectively incorporating texture and structure information into the classification procedure to detect urban building in Beijing by using Landsat7 ETM⁺ panchromatic image.The results indicates that the texture and structure information are effectively incorporated into the classification procedure with PCA and are helpful to detect urban building to achieve the accuracy of 81.33%.Besides, the results show that Landsat7 ETM⁺ panchromatic image can be regarded as a good alternative of spot panchromatic image in urban building detection with the identical ratio of the two results reaching 89.42%.