CHILD SAFETY SEAT

A child safety seat includes a seat portion, a backrest assembly including a first and a second backrest portion slidably connected with each other and a headrest slidably connected with the second backrest portion, the first backrest portion being connected with the seat portion, and a backrest adjusting system disposed on the backrest assembly and configured to provide a first stage of height adjustment where the first and second backrest portions are locked with each other and the headrest is movable relative to the first and second backrest portions for adjustment, and a second stage of height adjustment where the second backrest portion is locked with the headrest and unlocked from the first backrest portion so that the headrest and the second backrest portion are movable in unison relative to the first backrest portion for adjustment.