To provide a polypropylene-based resin composition having excellent balance between light weight and rigidity, and also having excellent dimensional stability, flowability and recyclability of a heat source; and to provide a molded article thereof.

The polypropylene-based resin composition comprises (A) 100 pts.wt. polypropylene resin, (B) 0.5-100 pts.wt. carbon fiber having >2 and ≤15 μm fiber diameter and 1-20 mm fiber length, and (C) 0.01-5 pts.wt. nucleating agent selected from the group consisting of a metal salt of an aromatic carboxylic acid and the like. The polypropylene resin of the component (A) is selected from a propylene homopolymer (a) having 1.5-2.5 die swell ratio, 7-13 Mw/Mn, ≥96% isotactic pentad fraction, and 20-100 g/10 min MFR, and a polypropylene block copolymer (b) comprising the propylene homopolymer (a) and a propylene copolymer obtained by copolymerizing propylene and an α-olefin.