It is an important method to improve the comprehensive properties of metal matrix composites by introducing nano-ceramic particles into the alloys. In the present work， the research status of in-situ TiB₂/Al composites was summarized from three aspects： the preparation methods， the microstructures of the composites under different processing techniques， the mechanical properties of the composites. TiB₂ particle reinforced aluminum matrix composites prepared by in-situ methods have the advantages of small particle size and good interface bonding with matrix. The dispersion of nano-TiB₂ particles can be modified through alloying design， hot working and rapid solidification. Compared with metal matrix composites prepared by external method， in-situ TiB₂/Al matrix composites have excellent mechanical properties， such as elastic modulus， strength， fatigue resistance， creep resistance and so on.