An ultrasound observation system includes: an image processing unit that generates an ultrasound image based on an ultrasound signal obtained by an ultrasound endoscope configured to transmit ultrasound to a subject as an observation target and receive the ultrasound reflected from the subject； a display unit for displaying the ultrasound image； a multiple input reception unit that simultaneously receives inputs at multiple points on the ultrasound image on the display unit, with a single touch operation； an input information determination unit that determines the number of the inputs and positions of the inputs； an operation mode setting unit that sets an operation mode related to the ultrasound image, based on the number of the inputs； and a target region setting unit that sets a target region to be processed corresponding to the operation mode, based on the positions of the inputs.
