In recent years, much effort has been devoted for the synthesis of inorganic semiconductor micro/nanostructures with controlled size and shape, because of their potential applications in solar energy conversion, catalysis, optoelectronic devices, ultrasensitive detection, and so on.[1].The catalytic activity of semiconductor catalysts is not only related to the size of catalysts but the morphology.Semiconductor catalysts with high-index facets usually have higher catalytic activity than those with low-index facets due to the presence of a greater density of the dangling bonds and atom steps in high-index facet.However, the surface energy of high-index facet is also higher, which results in the faster rate of crystal growth in the direction perpendicular to a high-index facet than that along the normal direction of a low-index facet, and then the rapid disappearance of high-index facet during crystal growth.Therefore, it remains a challenge to synthesize the semiconductor micro/nanostructures with high-index facets.We summarize our recent research progress in the chemical control synthesis of inorganic semiconductor micro/nanostructures with high-index facets mediated by organic structure-directing agents for highly efficient photocatalysis.The organic structure-directing agent can preferentially bind on a certain facet of the crystal, and then control its growth.This facile synthetic route could provide a good starting point for the research of morphology construction and shape-dependent catalytic properties of other materials.