We report the decay dynamics from the highly excited vibrational levels of the E 0g + (3P2) ion-pair state of I2. Strong UV fluorescence belonging to the D 0u + (3P2) → X 1 ςg + transition was observed upon the excitation of the E 0g + (3P2) (vE = 77 and 78) state. The vibrational levels populated in the D 0u + (3P2) state were found to be located at slightly higher energies than the vibrational levels of the laser-excited E 0g + (3P2) state. The vibrational levels populated in the D 0u + (3P2) state were restricted to those which have relatively large Franck-Condon factors between the laser-prepared vibronic levels. The absorption and stimulated emission rate in the presence of thermal radiation strongly suggests that the population in the D 0u + (3P2) state was induced by the absorption of blackbody radiation. The energy partitioning process in the high vibrational levels in the E 0g + (3P2) state was found to be totally different from that in the lower levels (vE = 0-2) where amplified spontaneous emission was a major relaxation pathway.