Provided is a resin blend including a first resin and a second resin, the second resin having a hydrophobic functional group in a side chain and having a surface energy difference of 0.1 to 20 mN/m from the first resin at 25° C., wherein the resin blend is capable of forming a layer separation structure. Also, provided are a pellet, a method for preparing the same, and a resin molding article having a specific layer separation structure. The resin blend may not only improve mechanical properties and surface hardness of the molding article but also shorten process time, increase productivity and reduce production cost by omitting an additional surface coating step.