A push button type belt buckle includes a moveable rod and a push button arranged to be interlaced with each other and configured to cooperate with spring mechanisms provided in a belt base. With such a unique structure, a buckling pin provided on the moveable rod is able to floatingly buckle a belt with ease while exhibiting an elastic characteristic capable of returning to its original position such that the adjustment of the extent of the fastening and buckling of the belt can be advantageously achieved via the push button reliably and such that the push button type belt buckle of the present invention is of the improved effects of facilitated operations and simplified assembly requirements and functions.