an operating mechanism disposed on a handle bar of a baby carriage for actuating locking mechanisms disposed at opposite ends of the handle bar and which locks the handle bar at a predetermined position or locks the baby carriage in a folded or an unfolded position . the handle bar has a hollow tubular construction and is bent in a u - shape or an inverted u - shape as viewed from its front . the operating mechanism includes a pair of slide members each of which is slidably disposed at the central portion of the handle bar , operating wires inserted into the handle bar , each of the operating wires having an upper end respectively retained by each of the slide members and a lower end attached to the locking mechanisms , and slide guide projections projecting from upper and lower sides of each of the slide members and an operating grip rotatably mounted on the surface of the handle bar , the operating grip having u - shaped guide grooves formed therein into which the slide guide projections are received . in this manner , the slide members can slide in the horizontal directions in the handle bar in response to rotation of the operating grips to thereby actuate the locking mechanisms .