To provide a method of quantitatively finding the content of an ethylene-propylene copolymer in a product polypropylene resin particulate material, and a method of quantitatively finding the fluidity index of the product polypropylene resin particulate material to evaluate the tackiness with good precision.

At least three particulate materials of a raw material propylene homopolymer particulate material and at least two product polypropylene resin particulate materials whose contents of ethylene-propylene copolymers are known and different from each other are loaded and consolidated, respectively, to obtain samples, and the tensile break strength value of each of the samples is measured, and a calibration curve is made from the contents of the ethylene-propylene copolymers in the particulate materials and the measured tensile break strength value. Then, a product polyropylene resin particulate material whose content of the ethylene-propylene copolymer is unknown is consolidated in the same state as above to obtain a sample, and on measuring the tensile break strength value of the consolidated sample, the content of the ethylene-propylene copolymer is quantitatively found from the calibration curve and the tensile break strength value.