The paper presents a spatial-color model of object and develops an efficient visual tracking algorithm based on particle filter. This spatial-color model captures richer information than the general color histogram because it incorporates spatial distribution of pixels in addition to color. In order to fast compute the weight of each particle, the Integral Images for computation of histogram, mean and variance are proposed, with which the parameters of spatial-color histograms can be computed by using only simple arithmetic operations and thus the computation load is reduce to linear complexity. Experiments on real image sequences show our method results in more accurate tracking than a standard color particle filter.