Abstract: The long-term deformation characteristics of high-performance concrete are discussed based on the results of concrete creep tests for two bridges. It is pointed out that aggregate is the most effective of the three quality factors of concrete, cement, admixture and aggregate, for enhancing the elastic modulus and reducing the creep shrinkage. A modification method and calculation formulas for the humidity-dimension of creep are presented, and the creep modification of reinforced concrete, temperature effect of creep behavior and the long-term creep are discussed.