Provided are an ultrasound system and method for providing a guide line corresponding to a pathway through which a needle is introduced or inserted. The ultrasound system includes an ultrasound data acquisition unit that transmits an ultrasound signal to a living body into which the needle is inserted, receives an ultrasound echo signal reflected from the living body, and acquires ultrasound data corresponding to each of a plurality of ultrasound images, and a processor that generates the plurality of ultrasound images by using the ultrasound data, creates a mask image for detecting a position and an angle at which the needle is introduced, detects the position and angle by using the mask image, and sets a guide line of the needle on the ultrasound image by using the position and angle.