Two-dimensional \alpha-MoO3 semiconductor material having wide band gap can be potentially used in a wide range of UV-light detection application. Here, we grown the large-scale film composed of \alpha-MoO3 microplates by using chemical vapor deposition process and fabricated a UV detector. The X-ray diffraction and Raman spectroscopy confirmed the continuity and crystallinity of the deposited MoO3 film on SiO2/Si substrate. The device exhibited a high responsivity of 500 mA/W and a photo/dark current ratio of over 6 and a significant fast response time under UV-light (360 nm) irradiation. An efficient UV-light detection of the MoO3 microplates can be attributed to the depletion-layer modulation process. © 2019 IEEE.