The binding energy of exciton in quantum dots with a parabolic confinement potential was calculated by variational methods beyond the Kohn-Luttinger effective mass theory, when the central-cell correction was taken into have assumed that a short range potential with two parameters for strength and range for exciton, representing the center-cell effect also depends on dot size. Our result is in good agreement with experiment. | Binding energy of exciton in quantum dots with the central-cell correction depending on the dot sizes