The effect of electron beam irradiation on magnetic property of iron bearing minerals was investigated by susceptibility measurements. The results show that the magnetic susceptibility of iron bearing sulfide minerals can be enhanced remarkably by strong beam current irradiation, while the magnetic susceptibility of oxidized iron minerals keeps unchanged and even is slightly reduced. The magnetic susceptibility of arsenopyrite can reach the ferromagnetic level. The particle size of irradiated minerals makes notable effects on magnetic susceptibility. The magnetic susceptibility of irradiated minerals is enhanced greatly with reduction of particle size, and the irradiation dose corresponding to the maximum magnetic susceptibility is decreased simultaneously. Exposure of pyrite to small beam current electron irradiation can only enhance its magnetic susceptibility from 4 to 5-fold. Enhancement of magnetic property by radiation induced defects and excitation in minerals is limited. Strong beam current electron irradiation provides a novel approach to enlarge the magnetic property differences between iron bearing minerals.