An object of the present invention is to provide a method for enhancing the emulsification ability of gum arabic.The present invention can provide a modified gum arabic having an excellent emulsification ability without coloration and/or unpleasant odor, by a method which has a step of making unheated gum arabic into an aqueous solution having a concentration of not higher than 50 mass %, and a step of maintaining the aqueous solution below 60° C. for at least 6 hours. The gum arabic modified by the method of the present invention can be used as an emulsifier for use with beverages, confectioneries, chewing gums, oil-soluble flavors, oil-soluble colors, oil-soluble vitamins, etc.