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TiO₂ powders showed a broad emission band. The peak position of the emission band for rutile powders was about 450nm, and that of anatase powders was about 500nm. The time-resolved photoluminescence of TiO₂ powder was investigated with 30ps laser pulses at 355 and 266nm. Decay profiles of emission were successfully traced by the extended exponential equation. In the case of rutile powders, the lifetime of the emission lengthened in the relation to the increase of particle size. Their lifetime was also dependent on the wavelength of excitation; i.e., it was longer at 355nm of excitation than at 266nm. Based on these results, the decay profiles of rutile particles were concluded to be determined by the migration of carriers from the bulk of the particles to the surface. In contrast, the decay profiles of the emission of small anatase particles were considered to be determined chiefly by the recombination process …