The present invention relates to a polypropylene-based resin composition including: (A) a polypropylene resin in an amount of about 40 to 90 wt %, (B) a metal hydroxide in an amount of about 1 to about 25 wt %, (C) an inorganic filler in an amount of about 5 to about 15 wt %, and (D) a polyolefin-based elastomer in an amount of about 0 to about 20 wt %, and a method for manufacturing the polypropylene-based resin composition.Accordingly, the polypropylene-based resin composition may be applied widely to a molded product of interior or exterior parts of a vehicle because a polypropylene resin composition containing a metal hydroxide may be used to manufacture interior and exterior products of a vehicle, thereby achieving weight reduction due to excellent foaming quality during the foaming injection and improved mechanical properties.