As an activity to build a new test facility for superconducting CICCs (Cable In Conduit Conductors), an insertion coil for an upgrade of the existing CS (central solenoid) model coil of KSTAR was designed and analysed to implement a superconducting magnet system being capable of pulsed operation up to 12 T. On the basis of a developed winding scheme of the insertion coil, some candidates of CICC design were proposed according to the result of an optimization method and a numerical code examining the thermo-hydraulic stability of CICC. After the design of winding pack and CICCs, we investigated thermo-hydraulic behaviors of the superconducting magnet with respect to given scenarios to estimate the limit of safe operation in pulsed mode.