The endoscopic paranasal sinus surgery is conducted under local anesthesia. The patient keeps consciousness. So, they feel pain and fear of surgical procedures. Pain and fear put a lot of stress on patient and affect the physiological variability such as increasing heart rate, elevating blood pressure and so on. To evaluate effects of surgical procedures on patient mental strain, the heart rate variability of 7 patients were measured. As results of analysis, characteristic fluctuations in heart rate caused by differences among types of surgical sections (wait, break, bone and mucosa cutting, blood aspirating, insertion and removing a piece of styptic cotton) were found.