Provided is a masterbatch in which blocking in a masterbatch of a hindered amine compound and a benzoate compound, which is caused by long-term storage under a high-temperature environment, is improved. Also provided is a mixed pellet comprising a mixture of (A) a masterbatch pellet that comprises not less than 30 parts by mass of a hindered amine compound represented by the following Formula (1) with respect to 100 parts by mass of a polyolefin resin and (B) a masterbatch pellet that comprises not less than 30 parts by mass of a benzoate compound represented by the following Formula (2) with respect to 100 parts by mass of a polyolefin, the mixed pellet wherein not less than 70% by mass thereof as a whole is composed of the masterbatch pellets of (A) and (B):