A lateral protecting mechanism adapted for a child carrier, wherein the lateral protecting mechanism comprises: a protecting block adapted to be pivotally disposed on a lateral portion of the child carrier and pivotally switchable between an unfolded position and a folded position; a locking component adapted to be slidably disposed on the lateral portion of the child carrier and slidably switchable between a locking position and a releasing position, the protecting block being allowed to pivotally switch between the unfolded position and the folded position when the locking component is located at the releasing position, the locking component being allowed to slide between the releasing position and the locking position when the protecting block is located at the unfolded position or the folded position, and the protecting block being restrained from leaving from the folded position when the locking component and the protecting block are respectively located at the locking position and the folded position; a driving component adapted to be movably disposed on the lateral portion of the child carrier and located at a position corresponding to the locking component for driving the locking component to slidably switch between the locking position and the releasing position; and an operating component adapted to be movably disposed on the child carrier and coupled to the driving component for driving the driving component to drive the locking component to slide to the locking position when the operating component is operated, wherein the operating component is adapted to be disposed on a seat portion of the child carrier, characterized in that the operating component is adapted to be combined with a strap disposed on the seat portion of the child carrier, and the strap operates the operating component to drive the driving component to drive the locking component to slide to the locking position when the strap is fastened. a protecting block adapted to be pivotally disposed on a lateral portion of the child carrier and pivotally switchable between an unfolded position and a folded position; a locking component adapted to be slidably disposed on the lateral portion of the child carrier and slidably switchable between a locking position and a releasing position, the protecting block being allowed to pivotally switch between the unfolded position and the folded position when the locking component is located at the releasing position, the locking component being allowed to slide between the releasing position and the locking position when the protecting block is located at the unfolded position or the folded position, and the protecting block being restrained from leaving from the folded position when the locking component and the protecting block are respectively located at the locking position and the folded position; a driving component adapted to be movably disposed on the lateral portion of the child carrier and located at a position corresponding to the locking component for driving the locking component to slidably switch between the locking position and the releasing position; and an operating component adapted to be movably disposed on the child carrier and coupled to the driving component for driving the driving component to drive the locking component to slide to the locking position when the operating component is operated, wherein the operating component is adapted to be disposed on a seat portion of the child carrier, characterized in that the operating component is adapted to be combined with a strap disposed on the seat portion of the child carrier, and the strap operates the operating component to drive the driving component to drive the locking component to slide to the locking position when the strap is fastened.