Hygrothermal properties of carbon fiber reinforced resin matrix composites is one of the important
problems for structure application of advanced composites. With experimental research on domestic carbon fiber reinforced resin matrix composites CF3052/5284RTM, the basic mechanical properties of composites in different hygrothemal condition were tested, and the influence of hygrothermal condition on basic mechanical properties of composites was analysed. The results show that the effects of hygrothermal condition on basic mechanical properties of composites were different, and humidity has a larger effect than temperature, the domestic carbon fiber composites can keep higher tensile strength and shear strength in the hygrothermal condition, and hygrothermal properties is excellent.