Imagination is the lifeline of science fiction. In the 20th century, Chinese science fiction has produced the three distinct imagination modes of desire, possibility, and principles, conveyed through at least five expression techniques in neologisms, verisimilitude, temporal disjunction, situational extremes, and metaphorization. Although imagination is critical to the creation of science fiction, there are polarized views about its nature. A necessary task for the future development of Chinese science fiction is challenging false conceptions of imagination so as to establish more imagination modes.