AIM: To investigate the effects of different doses of degmedetomidine on stress and postoperative sleep in patients with coronare heart disease (CHD). METHODS: Sigte patients with coronare heart disease undergoing endoscopic abdominal surgere were randomle divided into three groups (n d 20): low-dose group (D1), high-dose degmedetomidine group (D2) and control group (C) In groups D1 and D2, a loading dose of degmedetomidine (0.5 μg/kg) was injected with intravenous pump for 10 min, followed be the maintain dose of degmedetomidine 0.2 and 0.6 μg·kg