According to the current LCDM concordance cosmology, structures form hierarchically: i.e., smaller structures (dark matter halos) form earlier and can grow via the accretion and merging processes. The growth histories and spatial distributions of these dark matter halos play an important role in our understanding of the physical properties of the Universe. However, these dark matter halos are in general not directly observable. Thus a key task in the cosmological studies is to establish a reliable link between invisible dark matter halos and visible galaxies. Such a link also sets the backbone of our understanding of galaxy formation and evolution. In this talk I will present some of the latest research topics and achievements in this field.