This research aims to produce learning materials of module based on REACT (Relating, Experiencing, Applying, Cooperating, Transferring) for acid-base topic which content and construct are valid. The designed module graded by panellist as Subject Matter Experts (SMEs) which consists of lecturer from chemistry departement of FMIPA UNP and chemistry teachers in high school. To collect data, content validity and construct validity questionnaire were used as the instruments. The data analysis technique used in this research were Content Validity Ratio (CVR) and kappa Cohen formula. For content validity, there were three items graded by the panellists which is the suitability of module content with REACT syntax, with critical thinking sub-indicator and with chemistry scientific knowledge. Furthermore, for construct validity there were four items graded by the panellist which are contents, language, presentation, and graphic component. The Content Validity Index (CVI) were 0.903, which obtained from analysis data result of content validity. In the other side, for construct validity, the average of kappa moment was 0.924 which categorized as very high.