Scouring is one of the important issues in river and coastal engineering. When a structure is placed on a river, its foundations should be laid within the river and its strength ensures the stability of the bridge. Local scour around the bridge piers is one of the threats to their stability. In addition to physical damage, there is plenty of damage to life and social problems during floods. Therefore, the prediction of how to create, expand and measure the scour hole around the piers and provide suitable methods for controlling and reducing local scouring, need extensive investigation. In general, there are two basic methods for protecting the bridges piers against the scouring phenomenon: increasing the material resistance around piers and reducing the strength of the erosion agents. The purpose of this study was to investigate the effects of simultaneous use of cable and collar on controlling and reducing local scouring in cylindrical and round nosed rectangular piers. In this research, a cylindrical pier with a diameter of 3cm and a round nosed rectangular pier with 3cm width and length to width ratio (L/b) of 2, 3 and 4 were used. Cable diameter ratio of 0.15 (D C /D P ) with a 15 degree curvature and a rectangular collar with a collar width to the pier diameter ratio (W/D) of 2 were used. The results indicated that with increasing L/b the scour depth decreases. In addition, the time development of scouring in the rectangular nosed pier is lower than that in the cylindrical pier. Also with an increase in L/b the scouring development time decreases further. The length of the rectangular round nosed pier reduces the energy and the strength of the horseshoe vortex and the increase in the L/b of the pier exacerbates this trend. The results showed that cables causes the strength of downflow and as a result the strength of horseshow and wake vortex decreases. Due to the increase in the length of the round nosed rectangular piers the efficiency of the cable is reduced. The pier cable efficiency for the cylindrical pier was 10.7%. Also, the pier cable efficiency for round nosed rectangular pier was occurred for ratio of L/b=2 and was 8.4%.The results showed the collar safety agent of the coupler caused delay in starting of the scour. The best collar efficiency for the cylindrical pier was 26.9%. Also, the pier collar efficiency for round nosed rectangular piers was for L/b=4 and equal to 55.4%. The pier collar efficiency for simultaneous use of collar and cable for cylindrical pier was 38.3%. Also, the pier efficiency for simultaneous use of collar and cable for rectangular round nose pier was for L/b=4 ratio and equal to 58.5%.With the taking the velocity profiles around the round nosed rectangular pier with a ratio of L/b=4, it was found that the phenomenon of separation of flow occurs at the front of the pier and in the inner region of the scour hole. On the other hand the phenomenon of separation of flow behind of the pier occurs in the outer area of ??the scour hole. Using the quadrant analysis on the upstream and downstream round nosed rectangular piers, the probability of a sweeping event is higher than other events in the scouring phenomenon. Key Words Local Scouring, Cylindrical Piers, Round Nose Rectangular Piers, Cable, Rectangular Collar.