Abstract: Continuous fiber reinforced ceramic matrix composites (CMCs) have outstanding mechanical properties. It is considered as a potential refractory material applied in aerospace fields. Study on CMCs' constituent properties has significant importance to the design, manufacture and engineering applications. In this paper, a method was prepared for assessing constituent properties of composites from hysteresis loops. The method is straightforward experimentally and provides values of constituent parameters directly. In detail, a hysteresis model in one dimension was constructed by shear-lag theory. The diverse effects of long and short matrix fragments on hysteresis behaviors were studied. And the hysteresis behaviors of a 2D-SiC/SiC composite were gained from tensile test. Considering the actual process of matrix cracking, all SiC matrixs was assumed to crack into long fragment. Values of four constituent parameters were calculated out: matrix cracking stress as 90MPa, residual stress as 19MPa, interfacial debond energy as 3.1 J/m² and sliding stress as 74MPa. Considering the influence of the few short fragments, the accuracy of calculations is analyzed. The calculations show a good dispersion and characterize the mechanical properties of 2D-SiC/SiC composites well.