A method of preparing a chlorohydrin composition, the method comprising: introducing a polyhydroxy aliphatic hydrocarbon, a catalyst, and a chlorination agent into a first reactor in which the temperature is maintained in a range of 50 to 200°C, wherein the polyhydroxy aliphatic hydrocarbon is a C 2 to C 20 compound that contains two or more hydroxyl groups bonded to different carbon atoms; discharging a first reactor effluent comprising water as a by-product from the first reactor; introducing at least a portion of the first reactor effluent into a water removal device to separate it into a water-rich layer and a water-deficient layer; introducing the water-deficient layer and an additional chlorination agent into a second reactor in which the temperature is maintained in a range of 80 to 200°C; introducing at least a portion of a second reactor effluent into a purification device for chlorohydrins to obtain a chlorohydrins concentrate; and mixing the water-rich layer and the chlorohydrin concentrate, wherein in the first reactor, a reaction product of the catalyst and the polyhydroxy aliphatic hydrocarbon is formed as an intermediate product, and the intermediate product acts as a catalyst in a chlorination reaction of the polyhydroxy aliphatic hydrocarbon, wherein the polyhydroxy aliphatic hydrocarbon comprises at least one compound selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 3-chloro-1,2-propanediol, 2-chloro-1,3-propanediol, glycerol, 1,2,4-butanetriol, 1,4-butanediol, and esters of these compounds, wherein the catalyst comprises an organic acid catalyst, the organic acid catalyst including at least one compound selected from the group consisting of a monocarboxylic acid, a dicarboxylic acid, a polycarboxylic acid, a malonic acid, a levulinic acid, a citric acid, a succinic acid and a propionic acid, wherein the water removal device is distillation column, characterized in that the first reactor effluent introduced into the water removal device includes 10 to 25 parts by weight of the total of the chlorination agent and the additional chlorination agent and 75 to 90 parts by weight of water so that the first reactor effluent forms an azeotropic mixture. introducing a polyhydroxy aliphatic hydrocarbon, a catalyst, and a chlorination agent into a first reactor in which the temperature is maintained in a range of 50 to 200°C, wherein the polyhydroxy aliphatic hydrocarbon is a C 2 to C 20 compound that contains two or more hydroxyl groups bonded to different carbon atoms; discharging a first reactor effluent comprising water as a by-product from the first reactor; introducing at least a portion of the first reactor effluent into a water removal device to separate it into a water-rich layer and a water-deficient layer; introducing the water-deficient layer and an additional chlorination agent into a second reactor in which the temperature is maintained in a range of 80 to 200°C; introducing at least a portion of a second reactor effluent into a purification device for chlorohydrins to obtain a chlorohydrins concentrate; and mixing the water-rich layer and the chlorohydrin concentrate, wherein in the first reactor, a reaction product of the catalyst and the polyhydroxy aliphatic hydrocarbon is formed as an intermediate product, and the intermediate product acts as a catalyst in a chlorination reaction of the polyhydroxy aliphatic hydrocarbon, wherein the polyhydroxy aliphatic hydrocarbon comprises at least one compound selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 3-chloro-1,2-propanediol, 2-chloro-1,3-propanediol, glycerol, 1,2,4-butanetriol, 1,4-butanediol, and esters of these compounds, wherein the catalyst comprises an organic acid catalyst, the organic acid catalyst including at least one compound selected from the group consisting of a monocarboxylic acid, a dicarboxylic acid, a polycarboxylic acid, a malonic acid, a levulinic acid, a citric acid, a succinic acid and a propionic acid, wherein the water removal device is distillation column, characterized in that the first reactor effluent introduced into the water removal device includes 10 to 25 parts by weight of the total of the chlorination agent and the additional chlorination agent and 75 to 90 parts by weight of water so that the first reactor effluent forms an azeotropic mixture.