A high-resolution electron microscope (HREM) was used to study molybdenum sulfide catalysts supported on anatase-type titania. A large number of MoS2 crystallites with lateral dimensions of 5-10nm were observed in HREM micrographs of the catalyst sulfided in a stream of H2S/N-2. These crystallites maintained epitaxial relationships with the anatase surface: for instance, (1 1 O) MoS2 // (0 0 1) anatase with [0 0 1] MoS2 // [1 1 0] anatase or (1 1 0) MoS2 // (1 1 0) anatase with 10 0 1] MoS2 // [O O 1] anatase. Because of these relationships, edge-bonded MoS2 crystallites were selectively formed on the anatase-type titania surface.