3D integration has become extremely significant while devices keep shrinking the size and minimizing power consumption. At the same time, heterogeneous integration based on 3D integration brings more and more opportunities in current electronic products and applications because of their flexibility and ability to integrate different substrates, functions, devices, and products together. Since 3D integration can be treated as a candidate to extend Moore's Law and a solution to fulfill the concept of "More than Moore". Key technologies of 3D integration are the key to the success. Among the key technologies, oxide bonding can effectively enhance the density of stacking and attract a lot of attention recently.In this invited talk, research results of low temperature oxide bonding of 3D integration will be reviewed and discussed. In order to achieve the best oxide bonding quality, surface condition optimization including the surface roughness and surface oxidation needs to be investigated. With development of oxide bonding technologies and demonstrations, 3D integration shows strong feasibility in next-generation electronic applications. This talk will also present the current oxide bonding advances, as well as current material development.