The atomic squeezing effect in the dissipative environment is investigated by means of the quantum theory of damping-density operator approach and numerical calculations. The effects on the atomic dipole squeezing effect produced by the atomic initial state and mean photon number of the thermal reservoir are discussed. The results show that the atomic dipole squeezing declines asymptotically to zero, and doesn’t disappear in finite time if the population rate in the excited state is higher than the ground state in the atomic initial state in the vacuum reservoir. However, the squeezing effect always disappears in the thermal reservoir, irrespective of the atomic initial state. With increase of mean photon of the thermal reservoir, the squeezing effect disappears faster.