Abstract: In order to study the viscoelastic thermal stresses in reinforced concrete structures, which is regarded as a kind of composite materials, the viscoelastic parameters of reinforced concrete are measured experimentally. The method of three-point loading was used in the creep test of the reinforced concrete beam. The recurrent analysis of experiment results is also conducted. It is shown that: 1. The method for measuring the viscoelastic parameters of reinforced concrete is effective; 2. The loading history must be considered in choosing the creep coefficient in thermal stress calculation, for it is an important effect on decrease of creep; 3. In this experiment condition, reinforcement has little influence on creep, and creep coefficient of reinforced concrete almost equals that of pure concrete.