The present invention relates to a method of preparing racemic or optically active D or L-±-glycerophosphorylcholine in large amounts by subjecting choline phosphate or a salt thereof, and racemic or optically highly pure (S) or (R)-3-halo-1,2-propanediol to a substitution reaction in a medium at high temperature in the presence of an inorganic base which increases the activity of the reaction. The method for preparing racemic or optically active D or L-±-glycerophosphorylcholine is cost-effective because of the use of starting materials which are inexpensive compared to those in a conventional method. Moreover, the method is simple and convenient because it is performed via a one-pot reaction without a separate purification process. In addition, it enables a large amount of racemic or optically active D or L-±-glycerophosphorylcholine, or a salt thereof, to be quantitatively produced in a medium without side reactions by using the inorganic base which increases the reaction activity.