To provide a cement-reinforcing fiber being a hydrophilized polypropylene fiber, exhibiting good dispersibility in cement and good physical bonding to cement, and giving a cement molding improved in flexural strength and flexural toughness.

The cement-reinforcing fiber is prepared by subjecting a monofilament fiber obtained by spinning polypropylene, drawing the spun polypropylene, and embossing the drawn spun polypropylene, having an average flatness i.e., a thickness/width ratio in a cross section of the fiber, in the range of 1/1.5 to 1/7 and a monofilament fineness of 200 dt or higher, and being in the form of a wave having an amplitude of 1 to 4 mm, a wavelength of 2 to 20 mm, and an amplitude/wavelength ratio of 1/2 to 1/5 to a surface treatment comprising oxidation or fluorination to give wetting tension of 40 mN/m or higher to the surface of the fiber.