BN_f/BN, BN_f/SiBN and BN_f/Si₃N₄ mini-composites were fabricated by Low pressure chemical vapor deposition/infiltration (LPCVD/CVI) process. The microstructure, tensile property and dielectric property of BN fiber bundle and these three mini-composites were investigated. Results indicated that BN fiber composed of h-BN with low crystallinity, phase structure of which unchanged after heat treatment at 650 _oC and 800 _oC. Amounts of micro pores with size of 50-500nm exist on the surface of BN fiber. Mean tensile strength of BN fiber bundle heat treated at 800 _oC is 94 MPa. Average tensile strength of BN_f/BN, BN_f/SiBN and BN_f/Si₃N₄ mini-composites were 68.8 MPa, 30.6 MPa and 26.2 MPa, respectively. Three mini-composites all exhibited brittle fracture behavior, owing to the modulus mismatch between fiber and matrix and strong interphase bond strength. Cracks cannot be effectively deflected and fibers cannot bear the load effectively. Real part of dielectric constant and dielectric loss were lower than 3 and 0.04, respectively, indicating good Electromagnetic wave transmitting property. BN_f/BN possessed the best comprehensive performance.