Double screening multiplicity stepwise regression has an obvious advantage in the regressive type analyst'between the multiple arguments and depelldent variables which are interrelative and interactive.There is a coupling relation between orange quality and weather-factors. The application of double screening multiplicity stepwise regression to the analysis of the weather-factors which has an effect on the orange quality is effective. Such weather-factors as light,tempeature and water,esp. the fiEst two,all have an effect oil the orange quality.The effect of multiple-factors is more obvious than that of single-factor.