The physics system consisting of coherent coupled-atom interaction with coherent single-mode cavity-field is proposed. Using the complete quantum theory,the evolution process of the system is studied.It is found that the quantum atom entangled states and light field entangled states can be transferred into each other under a certain temporal condition. Otherwise,the initial state of the atom or the light field entangled states can be completely preserved by controlling the time of the atoms interaction with the light fields.