Abstract
The paper took Nileke forest farm in western Tianshan Mountain as the test site, the reflecting spectral curve of the typical plant was measured using the portable outdoor spectrum radiometer. The reflectance spectral characteristics of vegetation were analyzed. Using spectral differential technology, different age classes of Picea Schrenkiana var. tianshanica were studied. The spectral characteristic parameters of their original spectral curve and the first order derivative spectra were extracted from visible light and near-infrared range. Accuracy factors of spectral feature extraction were analyzed. The analysis proved that it had common features with healthy green vegetation's. It was more efficient to to identify the characteristics of different age-classes of Picea Schrenkiana var.tianshanica and extract Picea Schrenkiana var.tianshanica forest at near-infrared range by using the first-order derivative spectra.