Disclosed is a method of preparing 3-hydroxytetrahydrofuran using cyclodehydration. More particularly, this invention relates to a method of preparing 3-hydroxytetrahydrofuran, including subjecting 1,2,4-butanetriol to cyclodehydration under reaction conditions of a reaction temperature of 30˜180° C. and reaction pressure of 5000 psig or less in the presence of a strong acid cation exchange resin catalyst having a sulfonic acid group as an exchange group. According to the method of this invention, 3-hydroxytetrahydrofuran can be economically prepared at higher yield and productivity than when using conventional methods.