Abstract: The present invention relates to an auto-exposing method of a digital photographic apparatus. In particular, the auto-exposing method includes the controlling of weightings that can lead to change exposure tactics therefor; still, such an auto-exposing method is capable of calculating new exposure tactics by itself in order to obtain proper exposure based on the weightings when a user set more than one variable therein as manual conditions. Moreover, the traditional elaborate calculating can be substituted by list checking of the present invention; wherein the list is built according to characteristic curves of the sensitometer through forecasting functions. Accordingly, the anticipative results list of the present method will be more precise than that of the mathematic calculating method, the number of calculations thereof will be less and the calculating speed thereof will be faster.