Design of test scenarios is necessary in software and system development and testing in the automotive domain. It is required to conform several standards though concept and definition of test scenario vary from syntax to semantics. This paper proposes an integrated metamodel of test scenario to conform the several automotive standards, focusing on both the syntactic side and the semantic side. The syntactic side refers OpenSCENARIO and SOTIF, while the semantic side refers NHTSA. Finally, we consider a tiny case study and comparison to the standards.