A polypropylene resin and a polypropylene resin composition are provided, which have excellent fluidity and foaming properties, and particularly in use for foam injection molding, allow molding with a narrow initial cavity clearance even if a large mold is used, and therefore can provide a thin, large-area foam-injection-molded article having good appearance. The invention relates to a polypropylene resin obtained by melt mixing a linear polypropylene resin, a radical polymerization initiator and a conjugated diene compound, wherein the polypropylene resin has a melt flow rate of more than 30 g/10 min and not more than 250 g/10 min as measured at 230° C. under a load of 2.16 kg; a melt tension at 200° C. of not less than 0.3 cN; and a loss tangent (tan δ) of not more than 6.0, the loss tangent being a ratio of loss modulus to storage modulus at an angular frequency of 1 rad/s in dynamic viscoelasticity measurement at 200° C., and also relates to a polypropylene resin composition for foam injection molding, containing the polypropylene resin.