Two-dimensional (2D) nanomaterials have received much attention in recent years, because of their unusual properties associated with their ultra-thin thickness and 2D morphology. Besides graphene which has aroused tremendous research interest, other types of 2D nanomaterials such as metal dichalcogenides have also been studied and applied in various applications including electronics, optoelectronics, energy storage devices, and so on. In this tutorial review, we will take MoS₂ as a typical example to introduce the latest research development of 2D inorganic nanomaterials with emphasis on their preparation methods, properties and applications.