Abstract: The spread through air space (STAS) in lung cancer refers to the presence of tumor cells in the airway outside the main tumor body in the form of micropapillary cell clusters, solid cell nests, or individual cells. The researches of lung cancer in recent years discover the significant value of STAS for diagnosis, treatment, and prognosis, therefore the World Health Organization designated it as a new invasive pattern of lung adenocarcinoma in 2015. Predicting the presence of STAS by medicine imaging has been the research highlight in recent years. Though the feasibility of predicting STAS by medicine imaging has been confirmed, more in-depth researches are necessary for establishing more reliable and accurate prediction method in medicine imaging. This article reviews the research progresses of pathology, clinical significance and medicine imaging on STAS.