There are disclosed a carbon fiber strand for reinforcement of thermoplastic resin, wherein a sizing agent containing a resin composition obtained by mixing a component [A], i.e. an acid-modified polyolefin copolymer having a weight-average molecular weight of 15,000 to 150,000, which has, as the main chain, an ethylene-propylene copolymer, a propylene-butene copolymer or an ethylene-propylene-butene copolymer and in which the main chain has been modified with 0.1 to 20% by mass of an unsaturated carboxylic acid, and a component [B], i.e. an acid-modified polypropylene having a weight-average molecular weight of 3,000 to 150,000, which has, as the main chain, a polypropylene and in which the main chain has been modified with 0.1 to 20% by mass of an unsaturated carboxylic acid, at a mass ratio of 1:20 to 10:5, is adhered to 100 parts by mass of a carbon fiber in an amount of 0.1 to 8.0 parts by mass; a method for producing the above strand; and a carbon fiber-reinforced thermoplastic resin containing the above strand.