The circular polyethylene floating fish cage system in accordance this invention which consists of a number of pairs of floating devices (1,2) of a floating fish cage with certain curvature and both ends of each floating device is equipped with inner membrane and outer membrane； a number of inner membranes and outer membranes which are used to seal each ends of curved floating device； a number of double rings (3) which joins the pairs of inner curved floating device and outer curved floating device； a number of fence pole / net hook (3a) to install the fence (4) and act as the net hook of the floating cage； a number of bolts and nuts to bind each end of the inner and outer curved floating device with other pair of inner and outer curved floating device through the bolt holes of the outer circle on the outer membrane； wherein the floating devices of the circular floating fish cage have a different length such that the inner curved floating device is shorter than the outer curved floating device which enables an assembly of a precisely circular floating fish cage.
