A great number of point defects are created in diamond by electron irradiation, most of which are charged. In this paper, we come up with an interesting thought to determine the charge states of these defects in diamond. The irradiated regions are exposed by high-energy electrons with a scanning electron microscopy (SEM), and then are characterized by the low temperature micro-photoluminescence (PL) technology. Some evidences to determine the charge states of defects are obtained by comparing the PL spectra between the cases with and without SEM exposure.