This paper proposes a method to improve the performance of the supervised classification from two aspects. Firstly, the global spatial and local spectral similarity is used to extend the labeled sample size (GLS). Secondly, extended subspace projection (ESP) which projects the original image to a lower-dimensional subspace is used to alleviate band redundancy. Finally, the two implements are combined with the sparse representation classifier (SRC) to optimize the hyperspectral image classification (HSIC). The proposed method is named GLSESP. Experimental results on real hyperspectral data set demonstrate the practicality and effectiveness of GLSESP for HSIC tasks.