Abstract: We collected some information about reflectivity of different situation of land-surface in the Tibetan Plateau in July, 2009.We collected total 850 curves of spectrum by the FieldSpec3 of Analytical Spectral Devices (ASD)., Inc.After studied these curves of spectrum, we obtained some usable information about desertification and grass land and rape field.The studied result to show that there was markedly different reflectivity respective land-surface.The reflectivity characteristic of desertification is relative smooth, from 350nm to 1800nm there are two Absorb valley respective 700nm and 1400nm, other show slow reflect trend, and there are different max respective land-surface.The reflectivity character of Rape field show the character of typical green plant, beginning with 350nm there is one Absorb valley nearby 550nm, then it show to reflect, and nearby 700nm again emerge one Absorb valley, then the reflectivity show sharp ascendant trend, it reach max nearby 740nm, then the reflectivity keep in high value, after 1300nm it show to drop.The reflectivity character of grass land shows has it of green plant and desertification.