Carbon fiber reinforced silicon carbonitride ceramic composite (C/SiCN) was prepared by rapid electro-thermal pyrolysis chemical vapor deposition using liquid hexamethyldisilazane as precursor. The density of C/SiCN is 1.75g/cm3 and with 15% porosity. Microstructure characteristics of C/SiCN were examined by transmission electron microscopy and scanning electron microscope equipped with energy dispersive spectrometer. The mechanical properties were characterized by three-point bending test. Microstructure observation displays a high degree of coalescence between SiCN matrix and fiber filaments, but there also exist plenty of micro-pores within fiber bundle. It is different from that of C/SiC composite made by chemical vapor infiltration. Mechanical test exhibits a mostly obvious nonlinear fracture behavior, which can be explained by typical toughening mechanism of long fiber-reinforced ceramic matrix composite.