The effects of paraffin addition on the optical properties and crystallinity of selfassembled SiO2 photonic crystal (PC) were examined using a silica nanopowder. The silica nanopowder was fabricated using the well-known Stöber process. During the evaporation process for self-assembly of PC, the nanopowder content was 0.05 or 0.2 wt%, the paraffin addition was fixed to 0.001 wt%, the process temperature was 80oC and the heat-treatment temperature after evaporation was 900oC. The addition of paraffin reduced the defects in the PC layer, thereby resulting in good crystallinity and transmittance. Our results suggested that paraffin can enhance the bonding force between silica nanopowders.