Abstract: The present baseball training bat is comprised of a hollow tube with a handle portion and a hitting portion. The hitting portion is substantially smaller in diameter than that on a conventional baseball bat for improving swing accuracy. The distal end of the tube has an internal thread. Interchangeable threaded weight plugs of different lengths and weights are provided. The weight of any selected conventional bat can be closely simulated by installing in the distal end of the tube a suitable plug to produce substantially the same total weight. The plugs are also provided in materials of different densities. A plug in a denser material is shorter than another plug of the same mass but in a less dense material. The balance of the bat is thus changeable without changing the total weight by substituting plugs of the same mass but of different densities and lengths.