The present disclosure relates to systems and methods for taking X-ray images. The method may include obtaining reference data associated with an object, the reference data including at least one of height data or historical data. The method may also include determining at least one of a start point or an end point of an imaging region associated with the object based on the reference data. The method may further include causing to take an X-ray image of the imaging region based on at least one of the start point or the end point.