The Scientific Reasoning Test is basically inseparable from the three aspects of the Scientific Literacy Test. This study aims to test the feasibility of the instrument for measuring scientific reasoning in terms of content validity, psychometrics, and constructs. The form of this research is Research and Development (Research and Development). In the instrument development research design using the ADDIE procedural model (Analysis, Design, Development, Implementation, Evaluation). This test was given to 194 high school students in Math and Natural Sciences class XII in the 2022-2023 academic year. Analysis of the validity of the test using Rasch modeling. The type of validity applied is Messick's validity which includes content validity, psychometric validity and construct validity consisting of content aspects, substantive aspects, structural aspects and external aspects. The results show that of the 50 questions made, there are 25 items that are feasible to use as measumenet in scientific reasoning test. This research contributes to the improvement of assessment practice in science education.