Lithium tantalate (LiTaO₃) is a very important material with various outstanding properties. In this paper, a LiTaO₃ microcube has been successfully synthesized using a hydrothermal method at 220 °C. The microcube is about 1 μm in diameter. The structure is characterized by FESEM, TEM and Raman investigation, and the results suggest that the microcube is constructed by nanolayers. To clarify the growth mechanism of the layered microcube, a time-dependent FESEM investigation is performed. Further investigation of PL, dielectric and ferroelectric properties indicate that there are lots of oxygen related defects among the layers, which is helpful for increasing the Curie temperature. The LiTaO₃ microcubes show application potential to be used as a pyroelectric detector material with high performance.