The Scour problem is one of very important problem in river and coastal Engineering. When the structure is placed on the river It, involves placement of columns on the river. As a result, the base is exposed to the scour . Determination of scouring is important because denotes the destruction of potential flow around structures. Therefore for safety of structures exposed to water it is necessary to prediction of Scour. According to the above, it looks essential Understanding the Scouring and even morimportant , The use of methods to reduce scour around the base of structures . More ways in order to control and reduce Local scour are done and used For single pier, While are designed for group pier. The most common way to reduction scour are collar, Vanes, slote around and on the pier. In this study, The effect of roughness in control And reduction in scouring around group pier Been investigated.for this reason, while investigating time development, Flow pattern around single pier and Double piers group have Been investigated. For this purpose, it have used From simple and Rough circular pier with Diameter of 30 mm and The distance between the center-to-center of pier was 2, 3 and 4 times the diameter of the pier and totally 14 cases were examined. In tests in order to registration of 3D and momentary speed In different sections of longitudinal and transverse, The ADV Speedometer device was used to determin velocity, turbulent Intensities and Reynolds stress. Experiment was done in a Channel in length of 7 m, Width of 32cm and Depth of 36cm with Particles of sand in 0.7mm diameter.Tests revealed Scour depth decreases by using roughness on pier Compared whit Without roughness piers.most of decline of Scour Is relevant to the case that both pier have roughness. So that When Distance of pier from each other was 2b, The final depth of Scour 44 percent reduced in back pier in Compared with singl pier Without roughness.studies on tension and Velocity profile Around pier have been shown Simultaneous presence of Horseshoe vortex and Flows downward in Upstream of flow.and in downstream of flow Presence of Rising vortex Due to creation lots of Irregularities in Flow structure. Results of examinations on group piers with roughness shown that creating roughness in Upstream on piers Due to Decrease The maximum velocity of downstream flow rate Compared whit One pier without roughness and group piers without roughness and Decrease power of Horseshoe vortex. as a result Depth Scour Reduced in comparison with that two cases. While approaching The central axis of the channel In cross-section, Like group piers without roughness ,RMS For all three Longitudinal , transverse and vertical Component increase.the value of turbulent Decrease in upstream compare with group pier without roughness while in downstream it has more Amounts compare with group pier without roughness. Keywords : Scour,pier,group pier, Flow structure