By means of the quantum theory and numerical calculations method, the entanglement time evolution of the two identical two-level atoms in Bell states interacting with the two-mode odd-even entangled coherent field is investigated by using Negativity. The effects ofthe atoms initial state, mean photon numbers of field, the degree of the entanglement for the entangled coherent fields, and the coupling strength of interaction between atoms on the Negativity are discussed. The results show that the two-atom entanglement state will forever stayin the maximum entangled state when the initial state is I?ll), while the Bell state |β00) atoms appear disentanglement most of the scaled time. For the state Iβ10) ， mean photon numbers of field can be a great help, and in the state I?Ol) the co叩li吨strength of interaction between atoms plays a major role in the two-atom entanglement.