For complex scalar fields (x ) and  (x ), we introduce the entangled states which are their common eigenvectors. The states possessing complete and orthonormal properties are a field-theoretical generalization of the Einstein-Podolsky-Rosen pair states in quantum mechanics. Based on the new representation, we obtain the complete and orthonormal states {q },r , the common eigenvectors of the charge operator and  (x ) (x ) , with which the charge lowering and raising operators can be naturally defined. The applications of our formulation are briefly discussed.