In material process, heat treatment can improve the mechanical properties of original materials. Depending on initial heating and cooling rate, the surface morphology, structure and composition can be changed. The quenching process highly controls the phase transformation, grain size distribution and thermal stresses of metal such as austenite, ferrite, bainite, and martensite for carbon steel. This paper visualizes the flow pattern of cooling fluid when it impacting the metal specimen during intensive quenching process by using the high speed camera. Moreover, the contact uniformity of coolant on metal specimen is evaluated by measuring the differential pressures. As a result, it is observed that the flow separation on the edge of the top surface and the re-attachment of cooling fluid on the side region of the specimen.