The entanglement character between a two-level atom and a two-mode field as well as two-level atoms in the non-degenerate two photons Tavis-Cummings model in the resonance and non-resonance cases have been investigated, and the analytical expression about entanglement is obtained. Based on two kinds of initial states, the effects of field frequency, atomic frequency and dipole-dipole coupling between atoms on the entanglement are shown in detail. The cases of resonance and non-resonance are compared.