Qualitative spatial reasoning has received a lot of attention in the areas of Geographic Information Systems, Artificial Intelligence, Databases and Multimedia. The basic theory and algorithm of spatial reasoning are developing and innovating continually. Direction relation reasoning is an important branch in the field of spatial reasoning. Applying the theory of interval algebra and rectangle algebra, a new reasoning method combining cardinal direction relations with rectangle algebra relations is presented based on the model of MBR (minimum bounding rectangle). By this means, the good calculating property of rectangle algebra is applied to spatial direction relation reasoning, and the following methods are realized such as transform method between MBR-based cardinal direction relations and rectangle algebra relations, composition and inversion operation of cardinal directions, judging method of convex relations in cardinal direction relations and the consistency check algorithm of direction relations.