It is very important to know the spectral characteristics for the sake of understanding the remote sensing data. The reflectance characteristics of paddy field canopies vary with time or observational condition (solar zenith angle, solar azimth angle, view zenith angle) . A number of field studies have clearified the effects of these conditions on grain canopy reflectance. Most of the field data used in these studys, however, were conducted only through the growing season in one year or by grains planted in pots. A series of authors' experiments were initiated in 1982 and continued from the spring to the autumn every year to 1987. In this study we described that the remotely sensed spectral data measured on the ground are influenced not only by the grain type, observational conditions and growing season but also by the solar zenith angle, solar azimuth angle and view zenith angle in relation to the scene. In this paper we reported the results from the investigation of these various fundamental properties.