Abstract: The atomic dipole squeezing effects in the system of a two-mode entangled states interacting with a Σ-type three-level atom were studied. We analyzed the effects of the degree of entanglement of the two-mode entangled coherent states, the ground state probability amplitude of atomic initial state, the detuning, and the mean photon numbers on the atomic dipole squeezing effects. The results indicate that the influence of the degree of entanglement of the two-mode entangled coherent states on the atomic dipole squeezing effects isn’t noticeable. While the atomic initial state is in the ground state or excited state, the atomic dipole squeezing effects can not occur. While the probability of atomic initial state in ground state is equal to that in the excited state, the atomic dipole squeezing reaches its maximum. The enhancing of the detuning results in the increase of the frequency of atomic dipole squeezing. When the mean photon number of mode 1 remains unchanged and the mean photon number of mode 2 increases, the depth of atomic dipole squeezing decreases and the frequency of atomic dipole squeezing doesn’t change.

Key words: quantum optics, two-mode entangled coherent states, Ξ-type three-level atom, atomic dipole squeezing