YFeO3 single crystal, as a novel magneto-optical material, has attracted much attention due to its remarkable properties of primary significance for technological applications. In this work, YFeO3 crystal was successfully grown by optical floating zone method. Some voids are observed in the polished surface. The voids are effectively decreased by denser feed rod. In the etching samples, hexagonal etch patterns, sub-grain boundary and concentric growth striations were observed by optical microscope and SEM. The formation mechanism of these defects was discussed, and effective measures to restrain these defects were also proposed.