A child trailer includes a body which includes a plurality of wheel assemblies at the bottom and a joint assembly at the front side to adjust the angle relative to the body. Hence the child trailer can be maintained at a desired angle to support standing of a child or holding of goods. The joint assembly includes a coupler at the front side to fasten the child trailer to the chassis such as a wheel axle, frame or handle of a stroller, thereby can facilitate standing of the child or holding of goods.