For the two last decades, the quasi-oedometric compression testing method has been widely employed to characterize the quasi-static and dynamic confined response of concrete and rock-like materials. It consists of compressing a cylindrical specimen tightly enclosed in a thick confinement vessel for determining the hydrostatic and deviatoric behaviors of these materials under pressure ranging from few tens to a thousand of MPa. Large capacity hydraulic press can be used for quasistatic loading whereas large-diameter Split-Hopkinson Pressure Bar can be employed to characterize the dynamic response of the tested samples. This chapter describes the principle of this testing technique, the processing method, validation tools provided in the literature and some key-results obtained regarding the influence of concrete composition, particles reinforcement, free water content and the loading-rates on the hydrostatic and deviatoric behaviors of concretes.