Abstract: According to the smallest net section's picture of 2D-C/SiC composite laminates with circular hole, the macroscopic pores distribution and the gradient of loco-regional material density inside of specimen were obtained. The tensile stress-strain behavior of 2D-C/SiC composite laminates was fitted by nonlinear curve, and the material density's influence on initial tensile module and tensile strength also was investigated by associating theoretical model simulation with experimental verification. The tensile nonlinear stress-strain behavior of 2D-C/SiC composite with different density were described successfully. The mechanics analytical finite element model was built by taking the material density inhomogeneity in the specimen internal into account, and the material tensile nonlinear stress-strain behavior also varies with its density. The prediction in the net section tensile strength values of open-hole specimen go along well with the experimental results.