H.C. Stuck HS Grade boron carbide (B4C) powders with multi-walled carbon nanotube (CNT) were sintered by Spark Plasma Sintering (SPS) method in a vacuum atmosphere to obtain highly dense and fine grained final ceramic products. Powder mixtures were densified by SPS at 1650 and 1725 degrees C using 40 MPa pressure for 5 min. The effects of heating rate, spark plasma sintering temperature and CNT additive on density, hardness, fracture toughness and microstructures of B4C-CNT samples are investigated. Density measurements were carried out using Archimedes method. Hardness and fracture toughness were examined by Vickers indentation technique. Scanning Electron Microscope (SEM) was used to observe microstructural investigation.