Abstract: A folding baby carriage comprises an open-state locking member 4 which locks an open state of a baby carriage by engaging with a reversing member 3, an operating member 6 which moves the open-state locking member to release a lock of the baby carriage, and a stopper 10 which is rotatably supported by a handrail member 7 and directly abuts on the open-state locking member 4 so as to prohibit movement of the open-state locking member 4. When the baby carriage is changed to a closed state, it is necessary to turn the stopper provided so as to be operationally and positionally separate from the operating member 6 first and then, in this state continuously operate the operating member.