ABSTRACTCarboxylated‐terminated liquid acrylonitrile rubber (CTBN) and epoxy resin (JEF‐0211) were coreacted with cyanate ester (CE) to form CTBN/EP/CE ternary resin systems. Further, the ternary resin system was applied as prepreg for carbon fiber composites with vacuum bag degassing molding process. CTBN/EP/CE ternary shape memory polymer (SMP) exhibited relatively high tensile strength, Young's modulus, impact strength, and excellent shape memory properties. Compared with CTBN/EP/CE ternary SMP, CTBN/EP/CE carbon fiber composites showed much higher mechanical properties, such as their tensile strength and Young's modulus were high to 570 MPa and 36.7 GPa, respectively. Furthermore, CTBN/EP/CE carbon fiber composites exhibited good shape memory properties, their shape fixity ratio and shape recovery ratio were more than 95% after 30 times repeating shape memory tests. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48756.