Nano-sized turbostritic-BN (t-BN) was fabricated through chemical process using boric acid and urea in this work. By the same method, the AlN powders coated with nano-BN were prepared too. The results of X-ray diffraction (XRD) and transmission electron microscope (TEM) revealed that nano-sized t-BN was synthesized at about 600°C in nitrogen gas and it surrounded the surface of AlN particles. High-density AlN/BN nano-composites were fabricated spark plasma sintering (SPS). Microstructure and properties of AlN/BN nano-composites (5~30vol% BN) were investigated. The h-BN flake particles were homogenously dispersed at AlN grain boundaries and within grains in the AlN/BN composites. A little nano-BN additions significantly improved the bending strength of the nano-composites. However, the bending strength was decreased with the BN content increasing. The thermal conductivity of AlN/BN nano-composites was investigated too.