The paper studied the variational process of leaf area index （LAI）

leaf chl orophyll density （CH.D） and Hyperspectral data with growing period. The correla tion between the hyperspectral data and LAI

CH.D of rice was also analyzed. Sp ectral derivative technique was used to suppress the effects of low frequency sp ectral noises on background （such as Soil and so on）. The derivatives of relfect ance spectrum can enhance the correlation and improve the precision of predictin g LAI and CH.D. Results show that the derivatives of reflectance spectrum and CH .D more markedly correlate with LAI at some wavelength; CH.D is more av ailable to express crop canopy spectral information than LAI.