Tensile tests of two-dimensionally braided C/SiC composites and three-dimensionally braided C/SiC composites had been carried out at room temperature. Some specimens had been unloaded during experiments. Acoustic Emission signals also had been collected during experiments. The following conclusions were arrived. The stress-strain curves of these two materials were of nonlinear characters, and there were no obvious linear segments on those curves. Failure characters of these two materials were different: There appeared ply pull-out for 2D braided C/SiC specimens and there appeared zigzag shape for 3D braided C/SiC specimens. Stress-strain curves of loading-unloading tests and Acoustic Emission signals of those two materials showed damage evaluation during tests. There were different AE counts and AE energy characters between two materials.