Hull form development of the medium size high speed fishery patrol ship was carried out in the CWC at Chosun university. Same size of 15 knots class fishery patrol ship was selected as a parent form(Model number : CU-015), and modified fore and after body hull form under the slightly lengthened lo be suitable for the operation at 20 knots. To minimize the breaking wave in the vicinity of fore body at high speed zone, high bulb and sharp entrance angle were adapted. Meanwhile, to enlarge the engine room space keeping high resistance and sea-keeping Performance, U-type stern hull form was developed. Although the hull form was highly constrained in being limited to modification of a parent hull form significant wave resistance improvement was made.