This research was conducted to study the effect of the concentration of ferromanganese slag and basalt as an additive material for the cement to produce the mortar composite. The mesh size of slag and basalt powder were varied from 325 to 400. Meanwhile, the PCC cement weights were varied from 10 to 40 % of the weight. The physical-chemical analysis shown that the slag and basalt have quality as a cement or pozzolan additive based on ASTM C618. The important content in the slag is 25.889 % of SiO2, 16.938 % of Al2O2, and 25.420 % of Fe2O3. Meanwhile in the basalt containing SiO2 of 48.463 %, Al2O2 of 20.143 %, and Fe2O3 of 11.510 %. Based on the physical test of cement on compressive strength that has been carried out for 325 mesh and 400 mesh samples, the results show that the compressive strength with the addition of slag and basalt powder has a higher value of compressive strength compared to normal mortar. The highest value of compressive strength was for 325 mesh at a concentration of 10 % at 45.2 Mpa and 400 mesh for the concentration of 10 % at 1.74 MPa. Whereas for standard mortar the compressive strength is 0.848 MPa. The results of XRF characterization can be determined by the presence of SiO2, Al2O3, Fe2O3, and CaO oxides.