During the last two or three decades, computational fluid dynamics (CFD) hasbeen widely used in the scientific research and the analysis and design ofengineering systems. Especially in recent years, CFD has been playing a moreand more important role in the design of aeronautical and astronauticalvehicles. So many design conditions for realistic aircraft have beendetermined directly from the results of CFD. However, users and developersof CFD today face a critical question: How can the confidence in modeling andsimulations be critically assessed? Verification and validation (V{\&}V) ofCFD are the primary methods for building and qualifying this confidence. Inthis paper, the state of the art of V{\&}V of CFD is reviewed. In theintroduction, we first discuss the background and importance of V{\&}Vin CFD, and then review briefly the history of V{\&}V. Secondly, thebasic terminology and methodology of V{\&}V are discussed, including several fundamental concepts, the definitions and the basic processes.Section three discusses the primary processes and methods of verification,including analytic solution method, manufactured solution method and gridconvergence analysis. Section four discusses the primary processes andmethods of validation, including validation tier hierarchy, flowclassification, and some guidelines for validation experiments. In the fifthsection, several applications of verification and validation are presented,including the typical Lax problem solved by WENO scheme and our DWENOscheme, hypersonic flows over the hollow cylinder/truncated flare and sharpdouble cone configurations presented by P. Gnoffo, supersonic side-jetinteraction for an axissymmetric body. Finally, some comments aremade with respect to the development of V{\&}V of CFD in China: (1) theimportance of flow classification research, (2) on software quality assurance, (3)on the international academic activities and successfuldatabases, (4) on standardizing our experiment data and documents, andbuilding our own database for CFD validation, (5) on an organization to manage theissues of V{\&}V in China, (6) on the editorial policy on numericalaccuracy in related Chinese academic publications.