Abstract: Carbon Fiber-Reinforced Polymer (CFRP) material is increasingly being used for the retrofit and repair of concrete structures. However, there is insufficient information on the environmental durability of CFRP, especially under aggravating environmental conditionings combined with sustained loads. The coupled effects of freeze-thaw cycle and sustained loads on the long term behaviour of CFRP were investigated. The CFRP specimens are subjected to freeze-thaw cycle in an unstressed state or loaded in about 30% or 60% of the initial ultimate load, and there involve, respectively, 50, 100, 200 and 300 times of freeze-thaw cycles in water solution. The ultimate strength, elongation and elastic modulus of CFRP are studied after coupled actions of freeze-thaw cycle and sustained loads. The test results indicate that the coupled action of a freeze-thaw cycle and a sustained load had an effect on ultimate strength and elongation of specimen, while did not have any significant effect on elastic modulus of specimen. A simple residual strength damage model of CFRP under a freeze-thaw cycle and a sustained load is presented.