Polyolefin resin composition

This invention provides a polyolefin composition comprising [A] 99-80 wt.% of a propylene-based block copolymer and [B] 1-20 wt.% of an ethylene-based or styrene-based elastomer, which is excellent in transparency, coloring property and dimensional stability. The [A] consists of a propylene homopolymer component and an ethylene-propylene copolymer component having respective limiting viscosities: etaPP, etaRC, weight %: WPP, WRC, and melt flow rates: [MFR]PP, [MFR]RC, as well as the [B] having a limiting viscosity: etaR and a melt flow rate: [MFR]R, in such a way that the relationships, (etaRC/etaPP)x(WPP/WRC)=0.2 to 3.0, ([MFR]RC/[MFR]PP)=0.3 to 4.0, (etaRC/etaPP)=0.7 to 1.2, (etaRC > 6.5, ([MFR]R/[MFR]PP)=0.3 to 4.0 and (etaR/etaPP)=0.7 to 1.2, can be established.