Objective To observe the effects of analgesia and sedation with dexemetomidine for chronic obstructive pulmonary disease(COPD) patients withdrawn from mechanic ventilation .Methods 48 cases of COPD patients withdrawn from mechanic ven-tilation successfully were assigned into 2 groups :Control group was given Midazolam and fentanyl for analgesia and sedation ;dex-emetomidine group was given Dexemetomidine with a dose of 1 .0 μg/kg ,the intravenous injection time was more than 10 min and the intravenous titration rate at 0 .2 - 0 .7 μg(kg ? h) ,targeting Ramsay grade :3 - 4 ,bispectral index (BIS) :65 - 85 ,and faces pain scale (FPS) :0 - 4 scores .non-invasive blood pressure(NIBP) ,heart rate(HR) ,saturation of pulse oxygen (SpO2 ) ,pressure of end-tidal carbondioxide(PETCO2 ) were detected continuously at 0 ,1 ,2 ,4 h after administration .Results Compared with control group ,systolic blood pressure(SBP) of dexemetomidine group at 1 ,2 ,4 h after administration significantly decreased (P < 0 .05) , HR did not differ significantly at relative time points (P> 0 .05) .7 cases in control group droped out for SpO 2 < 90% or PETCO2 escalation over 20 mm Hg ,The test failure rate of dexemetomidine group was significantly lower than that of control group (χ2 =6 .02 ,P< 0 .05) .Conclusion Analgesia and sedation with dexemetomidine in intensive care unit (ICU ) for COPD patients with-drawn from mechanic ventilation were safe and beneficial .