We propose a real-time phase visualization technique using a phase conjugating mirror. An image of the phase derivative is formed in a coherent optical differentiation system and reflected by the phase conjugating mirror. After passage of the reflected light through the original phase object, its phase variation is compensated and its amplitude vanation only remains. This amplitude value is the derivative of the phase function and is fed to a second coherent optical integration system. An image inradiance of the output of this system is proportional to the square of the phase variation. This allows a neal-time quantitative visualization of actual object phase. There are no limitations to the phase objects in relation to the fine structures and large variations. Design of the setup for implementation of phase visualization is discussed. Computer simulations and experimental results are demonstrated.