A child high chair includes a frame, a seat and a seat attaching mechanism. The seat is detachably assembled with the frame and includes a seat body. The seat attaching mechanism includes a first combining component, a second combining component and a latch. The first combining component is disposed on the frame, and a sunken portion is disposed inside the first combining component. The second combining component is disposed on the seat body to combine with the first combining component. An opening is formed on the second combining component. The latch is disposed inside the second combining component and pivots to the second combining component. The latch includes a protruding portion, which is adapted to protrude from the second combining component via the opening to detachably engage with the sunken portion.