The structural and magnetic properties of Co3O4-delta were investigated by both first-principles and experimental studies. The results of first-principles calculations indicate that the spin splitting induced by oxygen vacancies can lead to the net moment in the Co3O3.875. The density of states of Co3O4 shows a band gap of 2.2 eV, while the impurity states appear with the oxygen vacancies. Furthermore, the Co3O4-delta films with oxygen vacancies were grown on MgAl2O4 and SrTiO3 substrates by using reactive sputtering. The structural analysis reveals that the Co3O4-delta films are epitaxial. Consistent with the first-principles study, magnetism is observed in the Co3O4-delta films, which attributes to the oxygen vacancies influencing spin structure by superexchange interaction.