A child tray assembly adapted for a child seat is provided. The child tray assembly includes a first tray and a second tray. The first tray is slidably disposed on the child seat. The first tray includes a first tray body and at least one sliding track installed on the first tray body. The second tray includes a second tray body and at least one sliding latch slidably disposed on the second tray body, the second tray body being detachably combined with the first tray body by the at least one sliding latch.