Abstract: In traditional object tracking with particle filter, color histogram is often used as feature. But color histogram suffers from the interference of background and other objects in the scene which are of the similar color to the tracked objects. Also simple color histogram will fail when the objects are occluded. In order to solve these problems, inspired by hog feature, an overlapping sub-block color histogram is designed as the feature for particle filter tracking system to improve the tracking performance. Also based on the new feature, weight calculation and model update method in particle filter have been redesigned. Experiment has proved its effectiveness.