A method for adjusting weighting values in light metering is provided. An input image is divided into multiple metering zones. The input image includes a number of pixel data, and the metering zones correspond to a number of exposure weighting values. It is determined whether the color of each pixel datum of the input image is skin color. For each metering zone, an amount of the pixel data determined as the skin color is calculated. The corresponding exposure weighting values of the metering zones are adjusted according to the calculated results.