Disclosed are a
child restraint system and a positioning
assembly (100a, 100b) thereof. The positioning
assembly (100a) includes a first positioning component (1) and a second positioning component (2). A first track (21E1, 21E2, 21E1', 21E2', 21E3, 21E4, 21E5, 21E6, 21E7, 21E8, 121E1, 121E2) and a second track (22E1, 22E2, 22E1', 22E2', 22E3, 22E4, 22E5, 22E6, 22E7, 22E8, 122E1, 122E2) are arranged on one of the first positioning component (1) and the second positioning component (2), and a first sliding member (121a, 221a) and a second sliding member (121b, 221b) are arranged on the other of the first positioning component (1) and the second positioning component (2). The first sliding member (121a, 221a) is slidable along the first track, and the second sliding member (121b, 221b) is slidable along the second track. The first positioning component (1) is rotatable and movable relative to the second positioning component (2) along the first track and the second track wherein said first track is curved or circular and said second track is straight.