Abstract. This paper deals with inequalities for the volume of a convex body and the volume of the projection body, the L p -centroid body, and their polars. Examples are the Blaschke-Santaló inequality, the Petty and Zhang projection inequalities, the Busemann-Petty inequality. Other inequalities of the same type are still at the stage of conjectures.The use of special continuous movements of convex bodies provides a general approach to this subject. A family of inequalities, depending on a parameter p ≥ 1 and proved by Lutwak for p = 1 and p = 2, is obtained.