Abstract: Objective To analyze the set-up and displacement parameters of intensity modulated radiation therapy (IMRT) and its related factors for pancreatic cancer, so as to provide guidance for treatment precision. Methods Forty-three consecutive patients with pancreatic cancer treated with hypofractionated radiotherapy using tomotherapy in Chinese PLA General Hospital from January 2011 to December 2014 were enrolled in this study. The Megavoltage CT (MVCT) images before each treatment were registered with kilovoltage CT (KVCT) images with CT simulation. The setup errors of the left/right (x), superior/inferior (y), anterior/posterior (z) and transverse profile rotation (Roll) were recorded, and its related impact factors were analyzed. Results All patients had undergone 923 MCT scans. The average setup errors in the x, y, z and roll directions were (0.02±0.68) mm, (-0.34±2.41) mm, (0.52±1.03) mm, (0.08±0.26)°, respectively. The corresponding enlargement margins in the direction of x, y, and z were 5.38 mm, 14.19 mm, and 4.65 mm, respectively. The setup errors of z direction were significantly associated with chemotherapy and age (P＜0.05), and the setup errors of roll direction were significantly associated with gender (P＜0.05). There were significant differences of image guide radiation therapy (IGRT) between once daily and once weekly in the directions of x, y, z and roll (P＜0.05). The corresponding patients accounted for 25.6%, 9.3%, 25.6% and 14.0%, respectively. There were also significant differences between weekly intervals in the directions of x, y, z and roll (P＜0.05). The corresponding patients accounted for 23.08%, 17.95%, 10.26% and 10.26%, respectively. The patients with at least once significant difference in directions of x, y, z and roll were 51.2% in once daily IGRT and 51.3% in once weekly IGRT. Conclusion The application of IGRT and enlargement margins can reduce setup errors and improve the precision of radiotherapy in maximum extent. It is necessary for patients to undergo IGRT once daily, which will provide quality assurance of precise radiation for pancreatic cancer.