Disclosed are a novel montelukast 4-halobenzylamine salt, and a method for preparing a montelukast sodium salt by using the same. In the disclosed method, a montelukast 4-halobenzylamine salt represented by Formula 2 or a montelukast sodium salt represented by Formula 1 is prepared by obtaining a compound represented by Formula 3 from a compound represented by Formula 5, in the same reactor, without an additional obtaining process. In Formula 2, X represents F, Cl, Br or I.