The shape of nanostructure has important effects on their properties, therefore in this study, we have prepared and characterized three different morphologies of WO3 nanostructures i.e. nanorod, nanosphere and nanoplate for surveying shape effect on their photocatalytic properties toward degradation of Rhodamine B(Rh B) dye.Obtained results show that nanoplate WO3 in comparison with others has the best photocatalytic activity. According to SEM, and photocatalytic degradation results, the reason for this behavior is the sharp edges and corners of WO3 nanoplates. Because of their low coordination number, atoms located in the edges and corners of the WO3 nanoplates have more activity,adsorb more Rh B and therefore give more photocatalytic activity to the WO3 nanoplates. Using of different scavengers showed that hydroxyl radicals are mainly responsible for photocatalytic activity of WO3 nanoplates and nanospheres but for WO3 nanorods, superoxide radicals are the main photocatalytic degradation agents. The shape of nanostructure has important effects on their properties, therefore in this study, we have prepared and characterized three different morphologies of nanorod, nanosphere and nanoplate for surveying shape effect on their photocatalytic properties toward degradation of Rhodamine B (Rh B) Obtained results show that nanoplate WO3 in comparison with others has the best photocatalytic activity. According to SEM, and photocatalytic degradation results, the reason for this behavior is the sharp edges and corners of WO3 nanoplates. Because of their low coordination number, atoms located in the edges and corners of the WO3 nanoplates have more activity, adsorb more Rh B and therefore give more photocatalytic activity to the WO3 nanoplates. Using of different scavengers showed that hydroxyl radicals are mainly responsible for photocatalytic activity of WO3 nanoplates and nanospheres but for WO3 nanorods, superoxide radicals are the main photocatalytic degrada tion agents.