Independent Verification and Validation (IV&V)  has begun to be used in the verification phase of system development. In this paper, we present the document group which we call Reference Model that we are developing currently. The Reference Model is developed for the purpose of supporting the efficient implementation of the formal verification for requirements and design specifications in IV&V. The Reference Model shows what with formats the requirement and design specifications should be described. For developers side of IV&V, the Reference Model are useful to recognize the essential information and its notation that should be described in the document that is a target of formal verification. For verifiers side, by comparing the Reference Model and the target document of the formal verification, the Reference Models are useful to recognize which items and properties should be verified.