The novel properties of nanomaterials also encourage their use to improve the growth of different tissues. Nano structured ceramics can be synthesized; thus, they may have particle size, geometry and microarchitecture similar to physiological bone. In this study, mechanical and bioactivity properties of nanohydroxyapatite (nHA)-nano magnesium oxide (nMgO) and nano hydroxyapatite (nHA) -nano niobium (V) oxide (nNb2O5) composites were compared. 80 wt.% nHA-20 wt.% MgO (nMH1), 70 wt.% nHA-30 wt.% MgO (nMH2), 80 wt.% nHA-20 wt.% Nb2O5 (nNH1) and 70 wt.% nHA-30 wt.% Nb2O5 (nNH2) nano composites including non-toxic binder were shaped by using press. The composites were sintered at 1000 and 1100°C for 2 hours, then microstructures, mechanical and bioactivity properties were determined. The physical and mechanical properties were determined by measuring density, firing shrinkage, compression strength and Vickers microhardness (HV). Structural characterization was carried out with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The bioactivity properties were determined after soaking the samples in the simulated body fluid. Density, compression strength and Vickers microhardness values of composites increased with increasing sintering temperature. The best density, compression strength and Vickers microhardness values were obtained with 70 wt.% nHA-30 wt.% MgO (nMH2) composite sintered at 1100°C as 3,16 g/cm3, 135 MPa and 438 HV, respectively.