The concept of dark force always appears in comic fictions. In fact, dark forces indeed exist in our universe. From an astronomer’s point of view, I will present the observational evidence. In cosmology, they are called dark matter and dark energy, the two mysterious components in our universe. I will make a comparison between the dark matter and dark energy in cosmology and the dark force in fictions. I will show how these dark components affect the evolution of our universe and talk about the tremendous efforts toward understanding their nature.