Abstract： Objective To prospectively investigate whether any of the perfusion parameters would predict early tumor response to chemotherapy and/or radiotherapy and prognosis in non-small cell lung cancer (NSCLC). Methods In a prospective series, Perfusion CT were performed in 152 patients suspected lung cancer with 16-slice or 8-slice multislice CT. Contrast medium (50 ml) was injected at a rate of 4 ml/s with a power injector. The scanning delay was 10 seconds and the scanning time was 50 seconds. Among 152 patients,123 patients were proved lung cancer by pathology. With the perfusion 3.0 software, the parameters including blood flow (BF), blood volume (BV), mean transit time (MTT) and capillary permeability surface area product (PS) were calculated. The perfusion image quality was evaluated on a 4-1eveal scale. The treatment response after chemotherapy and(or) radiotherapy was assessed with Response Evaluation Criteria in Solid Tumors (RECIST) ,and then the relationship between perfusion parameters with early tumor response to chemotherapy and(or) radiotherapy was evaluated. Student t test and Kaplan-Meier estimates were used for data analysis. Results In 84 patients (68.3%), the perfusion image quality was staged level 2 (moderate) and level 3 (good). Among them, 35 patients with NSCLC were assessed with RECIST after chemotherapy and (or) radiotherapy. In these 35 patients, The BF of responders and nonresponders was (81.0±33.6)and (56.3±23.1) ml·min~(-1)·100 g~(-1), respectively, which was significantly different(t=2.393, P=0.023). The median PFS of low-BF group (BF≤80 ml·min~(-1)· 100 g~(-1)) and high-BF group (BF>80 ml·min~(-1)·100 g~(-1)) was 11.8 and 8.0 months respectively (P>0.05), and the median PFS of low-BV group (BF≤6 ml/100 g~(-1)) and high-BV group (BF>6 ml/100 g~(-1)) was 9.2 and 8.0 months respectively(P>0.05), both of them were not significantly different. Conclusion NSCLC in high perfusion are relatively sensitive to chemotherapy and/or radiotherapy, and the response rate is relatively higher, but the progress time is relatively shorter.