- We suggest a scheme to reconstruct a two-mode entangled state in cavity QED by using the interaction of a V-configuration three-level atom and by driving the cavity field. After the atomic interaction with the cavity fields, the probability of the atom being in its initial ground state is found to be directly related to the two-mode Wigner characteristic function. The Wigner function and the four-dimensional density-matrix elements can be obtained for the two-mode entangled field by simple transformations. We consider both the cases where two entangled modes are prepared in one cavity or in two spatially separated cavities. 1999 The American Physical Society.