One of the important requirements in the object detection and tracking is the extracting of efficient features to trackthe target in video sequence. The feature of colour in image is one of the most visual features widely used. The using ofcolour histogram is the most popular method for representing color feature. One of the problems of using colour histogram to represent feature is its lack of spatial information where it is used to represents statistical distribution of the coloursonly. In this paper a new similarity metric with multi block colour histogram of image is proposed. This metric will be used by an object tracking method where the similarity will be applied to get a decision of choosing the correct solution (location) of the object from many candidate locations