Moving foreground segmentation has been widely used for many infrared video applications.In this work,a metric is presented to evaluate the performance of infrared moving foreground segmentation objectively.This metric is constructed on the basis of the criterion in Joint Segmentation (JSEG).Difference image is the result of consecutive frame subtraction and the pixels of it are classified into two classes:changed pixels and fixed pixels.With making a comparison between the distributions of classes in segmented foreground regions and background regions,it can accurately reflect the difference between segmented foreground and background.If the difference is greater,moving foreground segmentation is better.Experiments are performed on variety situation of moving foreground segmentation,showing that the proposed metric is effective.