Study about wave and relative phenomena is important among researchers. This study investigates experimentally and numerically the effect of shape and angle of a piston wave maker paddle on velocity field and downstream wave profile. In experimental section, white light technique for evaluating wave profile and PIV technique to measure the velocity field and particle velocity profiles has been used. In numerical solution, Navier–Stokes equations in two dimensions have been solved by Fluent software. In this study the boundary layer is about 3cm and can be ignored. At first, one condition is selected that have good compliance with solitary wave. This condition has been surveyed experimental and numerical and validated with available theory formula about solitary wave. The experimental and numerical velocity profiles of particles under wave tip have very good compliance to each other and have about 7 percent error with theory. The effect of paddle’s angle and mean speed on downstream flow was investigated. In experimental section, paddle’s angles have 0, 15 and 30 degree from vertical position and in numerical section this angle is set 0, 5, 10, 15, 20, 25 and 30 degree. Wave paddle mean speed was set as 0.341, 0.38 and 0.43 m/s in both experimental and numerical studies. The motion of wave paddle in numerical solution exported from experimental tests and applied to boundary condition. Uncertainty of experimental test in white light technique and PIV technique was measured and was about 2 and 3 percent respectively. Wave height and tip velocity has not been obvious affected by wave paddle’s angle but they increased almost linear by increasing wave paddle’s mean speed. In addition, velocity profile of particles under wave tip was investigated. By increasing wave paddle’s mean speed in low paddle’s angle this profile is increased but in larger angles there are no changes. By changing in wave paddle’s angle in constant mean speed, there is no obvious change in the velocity profile. Velocity vector in numerical and experimental investigation shows a pattern similar to shallow water solitary wave because vortex size near to wave surface is same as channel floor and this is the property of shallow water waves. By calculating horizontal force per width unit on wave paddle in numerical solution in first second of paddle motion, paddle’s angle 20 degree have minimum horizontal force on paddle and has been selected for evaluating arc shapes for shape of wave paddle. In this angle, eight shape selected as paddle, four arc with two concavities. All of them are arc with angles 15, 30, 45 and 60 and two concavities toward beginning and end of wave channel. In constant arc angle, the shape that have concavity toward beginning of wave channel have less horizontal force on it. Best shape for paddle in 20 degree is 15 degree arc that its concavity is toward beginning of wave channel Key Words Wave maker effect, Ship side profile optimization, solitary wave, wave generation, Shallow water