High resolution spatial images have little band information.This study adopted multiband-enhancement method instead of spectrum-enhancement method to synthesize false color in order to highlight green information and prevent the loss of other image infoiTnation in the extraction of green information.Experiments were conducted in two ways:the synthesis by different proportions of bands and the synthesis by replacing some pixels at the threshold value.Results show that the former method was more applicable in production than the latter one,and the the latter method was influenced largely by the threshold value.To determine the proportion for the optimal false color synthesis,experiments indicate that a proportion of near red and green band 1:1 can meet the demand of highlighting green information and decreasing the loss of other color information.Based on the RGB color space model,six-color-evaluation was proposed to evaluate different proportions for false color synthesis.The algorithm of this evaluation was achieved by reading pixel values in TIF format on the platform of Visual C language.The result of the evaluation was consistent with the visual observation.