Upconversion inverse opal photonic crystals based on a luminescent matrix of Yb, Er co-doped Y 2 Ti 2 O 7 were synthesized, and their photoluminescence was investigated. By comparing the spectra of the inverse opals with that of the reference sample, the contribution of photonic band gap effect to the upconversion emission was observed in the Y 2 Ti 2 O 7 : Yb, Er inverse opals. Intensity of the green or red upconversion emission from Er 3+ was depressed when the overlapping between the photonic band-gap and Er 3+ ions emission band occurs.