A polycarboxylic acid cement dispersant that can exhibit high dispersing ability and allow deforming in early stages in the case of producing concrete products, whereby the turnover of a formwork is increased so as to improve productivity, and the method of producing such as concrete product are provided. The polycarboxylic acid cement dispersant which provides a cement composition having a penetration resistance value exponent of 55 MPa or more and a slump retention exponent of 80% or more, and the method of producing a concrete product which makes use of a copolymer derived by using monomer components comprising the monomer (A) as polyalkylene glycol unsaturated monomer, the monomer (B) as unsaturated carboxylic monomer, and the monomer (C) as sulfonic acid group-containing monomer.