There are many serious problems are directly associated with the flow pattern in the mold in the continuous casting of steel process. The nozzle flow plays an important role in determining the mold flow pattern and to minimize casting defects. In this work a new type nozzle designed for a slab casting mold is developed. The 3-D steady k-ε finite-volume model has been applied to study the turbulent flow in nozzle and mold, which predict velocities agree with the impeller measurements in the water model well. The results show that nozzles with a mountain bottom are more impressionable to problems from asymmetric flow and large fluctuation on the mold surface. The impact of liquid at wave bottom nozzle can suppress the jet flow effectively and reduce the velocity variation.