Abstract: This paper briefly described the problems on the lock gate of logway both in theory and experiment. The principle of the gate which can be opened and closed automatically without any machine is making bearing hinge to generate unbalanced moment by use of combination of its weight, water pressure, buoyance and friction. It is convenient in operation and simple in structure. This new type of gate can be used in the inlet of logway and may be of some practical value in wood transport engineering by water.