Lithium niobate on insulator (LNOI) provides the critical platform for the next-generation photonic integrated circuits demanded by the high-speed optical communications and optical information processing in the future. The recent advances in fabrication of a variety of key photonic structures and devices using LNOI chip manufacturing technology are reviewed. The fabricated LNOI photonic devices are used for demonstrating highly efficient and tunable nonlinear optical processes thanks to the large nonlinear coefficient as well as the strong electro-optic property of monocrystalline LNOI.