Abstract: The Chemistry properties of galaxies are regulated by many fundamental physical processes, including gas accretion, gas outflow, and star formation. These processes are known to be critical to shape the galaxies to be what we see today. Due to a lack of direct observations and complexity in the interplays between these processes, we still do not fully understand the properties of these processes and the exact roles they played in driving galaxy evolution. In this talk, I would like to discuss what we could learn in terms of this issue by studying the chemical properties of galaxies. To fully exploit the observational data, I will firstly focus on the observations of our Milky Way disk to understand the disk formation and then discuss more general integrated observations of external galaxies to reveal the physical processes that drive the galactic chemical evolution.