Methods and apparatuses for generating treatment plans to be provided to focused ultrasound therapy apparatuses are provided. The method includes receiving an area to which ultrasound is to be irradiated, determining a size of a focal spot in the area, determining locations of focal spots in the area to which ultrasounds are to be sequentially irradiated based on the size of the focal spot, such that each of the locations of the focal spots is farthest from locations of focal spots in the area to which ultrasounds have been previously-irradiated, determining durations and intensities of ultrasound irradiations based on the size of the focal spot and the locations of the focal spots, and generating the treatment plan to irradiate ultrasound based on the size of the focal spot, the locations of the focal spots, and the durations and the intensities of the ultrasound irradiations.