Abstract: Some wheat varieties were selected in this experiment, and different density treatments were arranged. The results were as follows: 1) Leaf Orientation Value (LOV) and Leaf Area Index (LAI) of wheat had different contributions to canopy spectra, for example, LOV affected greatly canopy spectra more than LAI in jointing stage, but LAI had more effects on spectra after the ground was near to be covered completely. 2) 20 treatments including different varieties and densities were arranged in this experiment, the result of cluster analysis showed that all these treatments can be parted into four clusters: A-erect type and low LAI, B-erect type and high LAI, C-horizontal type and low LAI, D-horizontal type and high LAI. Their spectral reflectance had obvious difference in 400-700 nm and 700-1 150 nm at jointing, which indicated that jointing stage was an important stage in plant type recognition. 3) There was an obvious distribution difference among different clusters in scatter plot (X=△R890, Y=R890), △R890 was the reflectance dispersion of booting stage and jointing stage. It was seen from the Y-axis direction that R890 of a horizontal type variety was higher than erect type ones, and seen from the X-axis direction, the greater △R890 was the lower population one within the same type varieties, which indicted that the combination of plant-type and the population magnitude can be identified qualitatively by this method.

Key words: Winter wheat, Plant type, Canopy structure, Hyperspectral