Abstract: The determination of minimum longitudinal reinforcement ratio of flexural concrete members in Code for Design of Concrete Structures (GB 500102002) is presented in this paper.And this paper compares the limit of the minimum longitudinal reinforcement ratio in Chinese concrete design criteria with other countries' criteria.The crack width of a bending member does not satisfy the criteria's limit requirement while minimum reinforcement satisfied through an engineering example.The paper suggests a new formula of the minimum reinforcement ratio,whose serviceability is taken into account to assure that the minimum reinforcement ratio is compatible with the crack control.