This May 10^th witnesses the success of hot commissioning of square and round billet caster of special steel smelting project of Xinxing Ductile Iron Co., Ltd. which is contracted by CISDI on EP basis. This commissioning produces 20# steel with diameter of round billet of Φ175mm, casting speed of 1.6~2.0m/min, and specific length of 3m. During this hot commissioning, two ladles are casted by the continuous caster, all the performance indicators reach the technical requirements and all the equipment runs stably. The successful operation of this project lays solid foundation for further cooperation between Xinxing and CISDI.