An empirical correlation, considering the temperature effect but no effects of interparticle forces, on the particle entrainment rate at the gas exit of the fluidized bed has been proposed on the basis of the comprehensive experimental data. The entrainment flux is considered to consist of a constant flux independent of freeboard height and another flux decreasing exponentially with freeboard height. The correlation successfully follows the measured trend where the entrainment rate increased after an initial decrease with increasing temperature and the minimum entrainment rate at a given temperature. The correlation also successfully describes the pressure effect showing that the entrainment rate increases with pressure.