This X-ray phase imaging system (100) includes an X-ray source (1), a detector (2), a first grating group (3), a second grating group (4), a moving mechanism (5), and an image processing unit (6). The moving mechanism is configured to relatively move a subject (T) and the imaging system (9) such that the subject (T) passes through a first grating region (R1) and a second grating region (R2). The image processing unit is configured to generate a first phase-contrast image (14a) and a second phase-contrast image (14b).