In this study, the effects of particle addition on the microstructure, mechanical properties and fracture behaviors of Al/B4C particle reinforced composite produced by hot pressing method were investigated. After the production of 5, 10 and 15 wt.-% of B4C reinforced composites, T6 heat treatment was applied. It was specified that a strong interface bond occurred between the matrix and particles, and during the fracturing of composites, this effect increased the particle fracture. It was observed that particles were fractured parallel to the fracture surface and to each other fracture surface of MMCp. In general, cavity of particle separated from the matrix was not seen. In the production of MMCp, it was also observed that hot pressing provided a density higher than 99 %. After the heat treatment the maximum hardness value of 173 HB was reached with 15 wt.-% B4C reinforced sample. The transverse rupture strength ( TRS) decreased with the increase of reinforcement ratio. The highest TRS was 510 MPa with the 5 wt.-% reinforced material, whereas the lowest value was obtained to be 387 MPa with the 15 wt.-% B4C reinforced material.