[en] Concrete is a materials with a complicated composition and microstructure. Though much knowledge regarding the mechanical properties of concrete materials has been obtained empirically, knowledge concerning its physico-chemical properties, such as diffusivity of radio-nuclides and chemical durability for long-term, is insufficient for the performance assessment of concrete materials used for fusion plants and waste disposal. Tritium, a major radionuclide to be managed in fusion plants, has some chemical and physical forms in concrete, which makes tritium migration in concrete more complicated. This article reviews tritium migration in concrete from a physico-chemical point of view. (author)