An X-ray imaging apparatus comprises an X-ray source for irradiating X-rays to a subject a sensor mounted on the source and a controller for obtaining a volume of the subject based on an output value of the sensor, determining a degree of obesity of the subject based on the volume, and controlling an irradiation level of the X-rays based on the degree of obesity of the subject, wherein the output value of the sensor comprises, if the sensor comprises multiple image sensors, tilting angles of the multiple image sensors while the X-ray source is being shifted. An X-ray imaging apparatus and method for controlling the same where characteristics, e.g., a degree of obesity, of a subject may be automatically detected. Based on the detected characteristics of the subject, an intensity of X-rays may be automatically controlled, thereby improving the quality of the X-ray image.
