Abstract: A leg support for a child tricycle having a cycle frame is disclosed. The leg support is characterized in that the cycle frame is provided with two spaced apart supporting board and the end edge of the supporting board is provided with a blocking board; and the top end of the leg support is pivotally mounted between the two supporting boards, and the length of a pivotal end of the leg support is adjustable such that the minimum length of the leg support allows the swinging of the leg support, and at the maximum length of the leg support the pivotal end urges the side edge or the bottom edge of the blocking board, providing the positioning of the leg support.