The present invention relates to a controlled release capsule preparation for oral administration, which contains (i) a granule containing a physiologically active substance which is a compound represented by the formula: wherein n is an integer of 1 to 3, and Ar is an aromatic ring optionally having substituent(s), or a salt thereof, and a hydrophilic polymer, and coated with an enteric coating agent and the like, and (ii) a fluidizer. According to the present invention, a controlled release composition for oral administration of an imidazole derivative, which has steroid C17,20-lyase inhibiting activity and which has remarkably improved sustainability of the blood concentration, is provided.