All available sources of the critical curves data of binary aqueous solutions and binary carbon dioxide containing mixtures have been collected, evaluated, and compared with various data sources and with prediction and correlation methods in this book. Various techniques of the critical parameter measurements for pure fluids and fluid mixtures and their accuracy were reviewed. Results of the critical analysis of the uncertainty of each data source along with comparisons with other sources were presented. The reliability, quality, and consistency of each critical property data set were examined. The most reliable critical parameters for binary H2O+solute and CO2+solute systems were selected and recommended for future scientific and industrial applications. Moreover, special interest has been focused on the description of thermodynamic and structural properties of the dilute mixtures near the critical point of pure solvent (water and carbon dioxide) using the critical properties data (initial slopes of the critical curves, the shape of the critical lines.