Methods of preparing an aromatic liquid crystalline polyester resin and an aromatic liquid crystalline polyester resin compound are disclosed. A method of preparing an aromatic liquid crystalline polyester resin may include: acetylating a first monomer including an amino group by a reaction with a carboxylic acid anhydride; acetylating a second monomer including a hydroxyl group and not including an amino acid group with an additional carboxylic acid anhydride; and synthesizing an aromatic liquid crystalline polyester prepolymer by a condensation polymerization reaction of the acetylated first and second monomers with dicarboxylic acid. A method of preparing an aromatic liquid crystalline polyester resin compound may use the aromatic liquid crystalline polyester resin prepared according to the forgoing method.