Abstract: By means of thermoelectric Actinometer mounted with eight coloured glass filters, the spectral intensities of the solar direct radiation were measured in ten stations, distributed in seven different regions in china, for various periods of time during 1975-1978.Based on 2698 series of data obtained from the observations, the effects of the solar elevation, season, geographical latitude and altitude above sea level as well as aerosol and water vapor on the solar spectral radiation are analysed. The relative fluxes of the solar spectral radiation in various spectral bands are tabulated with air mass, the atmospheric turbidity coefficient and absolute humidity at the surface as three physical parameters.