Hydraulic jump phenomenon has been remarked as one of the singular phenomena of Fluid Mechanics. And it has been reserched about the length of hydraulic jump and the relation of various quantity in a hydraulic jump, etc. In this treatise, we tried to analized a hydraulic jump on a momentum equation, using the equipment which generated hydraulic jump, about the steady jump and strong jump in our hydraulic laboratory. Practically, hydraulic jump length and its inside condition, which decide the apron length, and become a basic data about preventive scouring, in a sluice-gate or a dam. And then, it becomes neccesary to know the variation of energy in order that we know hydraulic jump length and its inside condition. In this point of view, we considered about the properties of hydraulic jump phenomenon.
