An in-situ luminescence measurement was performed in lithium oxide bombarded with 2 MeV He+ ions. The luminescence spectra were obtained in the temperature range from 300 to 850 K. During the ion bombardment. the luminescence peaks of broad widths were observed near 260, 380 and 510 nm and the equilibrium peak intensities decreased with increasing temperature. Another peak at 340 nm appeared above 550 K- After the ion bombardment. the 380 and 340 nm peaks were observed on the light irradiation of 310 and 260 nm. respectively. and were attributed to the F+ and F0 centers. The other peaks at 260 and 510 nm might be associated with the impurities such as hydroxides. The present technique is very useful to study the behaviours of irradiation defects under bombardment.