Van der Waals materials, characterized by their layered structures and weak interlayer interactions, have attracted significant attention due to their two-dimensional nature, highly tunable electronic properties and great potential for heterostructures. Intensive studies have been carried out on different van der Waals materials including graphene, transition metal dichalcogenides and more. In 2018, the realization of moiré superlattices built with graphene, most famous van der Waals material, has brought the field of condensed matter physics to a brand new stage. Beyond graphene, transition metal dichalcogenide (TMD) moiré superlattices have emerged as a versatile platform for exploring novel quantum phenomena such as correlation effects and band topology. In this thesis, we focus on the emergence of Chern insulators in different TMD moiré superlattices. Firstly, I will introduce general concepts related to van der Waals materials and experimental techniques. In chapter 2 and 3, I will show the the realization of Chern insulators in MoTe2/WSe2 moiré superlattices at filling factor ν=1 and fractional filling ν=4/3, respectively. In chapter 4, I will discuss our findings of both integer and fractional Chern insulators in twisted MoTe2 moiré superlattices. Our results demonstrate that TMD moiré superlattices possess great potential for realizing non-trivial band topology, with implications for future research in next generation device and topological quantum computing.