The cobalt ferrite (CoxFe3-xO4) magnetic nanoparticles were prepared by solution combustion synthesis route. Thermodynamic modeling of the combustion reaction showed that, while varying the fuel ratios, they produce fewer amounts of gases and final adiabatic temperature when increased to fuel rich condition resulted in single phase of CoFe2O4. The fungal activity on the prepared cobalt ferrite magnetic nanoparticles was investigated against Trichoderma viride and Penicillium antarticum. The results revealed that the cobalt ferrite magnetic nanoparticles induced the growth of the fungi when the concentration of prepared nanoparticles was increased.