The present invention provides an acrylic acid ester copolymer emulsion composition, and redispersible powders made therefrom. The acrylic acid ester copolymer emulsion composition comprises polyvinyl alcohol having a degree of saponification of 85 mol % or more, and an average degree of polymerization of 300 to 1400; hydrophilic ethylenic unsaturated monomers having a water solubility of 1% or more; hydrophobic ethylenic unsaturated monomers having a water solubility of less than 1%; and a lipophilic initiator. The acrylic acid ester copolymer composition according to the present invention has excellent polymerization stability, and improved water resistance, alkali resistance, and fluidity, and the redispersible powders prepared by a spray-dry of the acrylic acid ester copolymer composition have improved water redispersibility, and thus, can be used in various fields such as an additive to a hydraulic material, a powder paint, and an adhesive.