Bismuth ferrite crystal is synthesized by hydrothermal method. The effect of hydrothermal temperature, KOH concentration, supersaturation, cooling rate, and compactedness on the crystal phase and the morphology of product were investigated. The results indicated that BiFeO3 microcrystalline with good quality could been synthesized at 140-240 degrees C with KOH concentration of 4-14 mol L-1. In addition, it is favorable for improving the crystal quality to reduce the supersaturation and decrease the cooling rate. With the increasing of the compactedness, surface holes and cracks of the as-grown crystals would be reduced. The optimization of hydrothermal condition provides guidance to grow BiFeO3 crystal with a large size and high quality for practical application. (C) 2015 Elsevier B.V. All rights reserved.