We need three types of knowledge to support reading science fiction at least. Ontology knowledge is not only the lever to mobilize the other two kinds of knowledge to participate in reading, but also the key to avoid misreading, including stylistic knowledge such as concept, type, elements and boundary determination. In terms of type, science fiction is divided into two categories , in addition to the theory of “soft and hard”, the eight types determined from the perspective of subject matter are generally recognized by researchers. “Scientific elements”, “strange environment”, “humanistic thinking” and “logical self-consistency” are necessary elements of science fictions. Together with the literary attributes and scientific boundaries of science fictions, they define the creative territory and reading vision of this kind of novels.