The spectral library of Shan Mei Litchi Orchard in Zeng Cheng City, which was built on the basis of the spectrum of the representative litchi and its background parameter measured by Analyzed Spectral Devices(0.35~2.5μm), was transformed into the spectral library of TM band width. The digital number of TM image, which had been preprocessed, was transformed into ground surface reflectance. The litchi planting area information in Zhong Xin Town was extracted from Landsat 5 TM image through the building of the Linear Spectrum Mixture Model, of which end-members came from in-situ measured spectral library and TM image spectra. The results show that the extracting effect is contented with the expected mapping precision.