Abstract: To understand creep development law of high strength concrete in civil engineering， and discuss the impacts of stress combination on concrete creep， based on the assumption of a homogeneous continuous medium， a numerical model of porous medium for the concrete creep is established and verification of biaxial creep experiments are carried out. The research results show that the creep coefficient is closely correlated with stress status of samples; and the creep coefficient of biaxial stress status is smaller than that of a single stress status and highly effected by the vertical stress； and the creep coefficients for 180 days of computation and experiment results with the biaxial stress status are about 75% and 90% of those with the single stress status respectively. Construction quality of prestress in the course of construction of prestressed concrete structures must be well controlled, as an increase in the creep coefficients could be induced by the loss of prestress.