A shot pattern control wad structure for use in a cartridge for shotgun wherein the cartridge includes a case having a tubular outer wall and a wad structure located in the case between gunpowder and a charge of pellets. The wad structure of the present invention is a two-piece structure and includes a base wad having a tubular cylindrical body open at a forward end thereof and has a closed rearward end that faces adjacent to the gun powder. The cylindrical body of the base wad is provided with slits longitudinally extending from the open forward end. The second portion of the wad structure is a shot container having a tubular cylindrical body with open rear and front ends and contains the charge of pellets and is dimensioned to be slidably received within the base wad. The open front end of the shot container has an annular inwardly restricting extrusion passage for extruded passage of the charge of pellets therethrough and the open rear end of the shot container is preferably provided with longitudinal slits.