The role of SrTiO3 seed layer on low-temperature crystallization of Pb(Zr, Ti)O3 (PZT) film was investigated. The SrTiO3 seeds were prepared by pulsed laser deposition (PLD) with the temperature range of 400-600°C and PZT films were prepared by thermal MOCVD. The pyrochlore free PZT films can be successfully crystallized at around 340°C on SrTiO3 seed layers by thermal MOCVD. It was found that the role of SrTiO3 seed layer is not only pyrochlore suppression but also perovskite promotion. It is also considered that crystallinity, surface coverage and seed layer thickness are important parameters for low-temperature crystallization and electrical properties of PZT films.