The present invention relates to a plasticizer composition and resin composition and a method for preparing same and can provide a plasticizer and a resin composition comprising same, wherein the plasticizer can improve physical properties, such as plasticizing efficiency, migration, tensile strength, elongation rate, stress migration, and light stability, which are required from a sheet prescription when the plasticizer is used as a plasticizer of a resin composition, by making improvement on bad physical properties which have occurred due to structural limits.