Disclosed is a continuous casting nozzle having a refractory portion formed to contain a dolomite clinker and arranged to define a surface region adapted to be in contact with molten steel, which is capable of protecting a working surface of the nozzle from alumina build-up due to alumina in molten steel, while improving corrosion resistance, even during long-term continuous casting of molten steel. The refractory portion is prepared by adding a binder to a mixed material and subjecting the obtained mixture to kneading, forming and heat treatment. The mixed material comprises a dolomite clinker which has an average particle size of 0.8 mm or less and a CaO content of 50 mass % or less. The mixed material has a ratio W1/W2 of 0.33 or more, wherein W1 is a content by mass of CaO, and W2 is a content by mass of MgO. The mixed material comprises a dolomite clinker and a magnesia clinker. Alternatively, the mixed material comprises a dolomite clinker and a magnesia clinker. The mixed material has a ratio WD/WM in the range of 0.5 to 15, wherein WD is a mass % of dolomite clinker particles having a particle size of 1 mm or less in a particle size distribution of the dolomite clinker, and WM is a mass % of magnesia clinker particles having a particle size of 1 mm or less in a particle size distribution of the magnesia clinker. Further, the mixed material has a ratio W1/W2 in the range of 0.33 to 3.0, wherein W1 is a content by mass % of a CaO component in the dolomite clinker, and W2 is a content by mass % of an MgO component in the magnesia clinker.