Objective To observe and compare the characteristics of TCM syndromes and APACHE II scores with two mechanical ventilation modes,that is,non-invasive ventilation and invasive ventilation,in acute exacerbation of chronic obstructive pulmonary disease（ COPD） in order to optimize the therapeutic regime and provide evidences for determining the severity and prognosis of the disease. Methods 59 cases of AECOPD in ICU of Wangjing Hospital,China Academy of Chinese Medical Sciences who received mechanical ventilation from June 2014 to June 2016 were divided into non-invasive ventilation group of 32 cases and invasive ventilation group of 27 cases,and TCM syndrome types and APACHE II scores were compared. Results There were 10 cases（ 31. 3%） belonging to excess syndrome,14 cases（ 43. 8%） belonging to deficiency syndrome,8 cases（ 25. 0%） belonging to syndrome of intermingled deficiency and excess in the non-invasive ventilation group; and there were 5 cases（ 18. 5%） of excess syndrome,6 cases（ 22. 2%） of deficiency syndrome,16 cases（ 59. 3%） of syndrome of intermingled deficiency and excess in the invasive ventilation group. APACHE II scores of invasive ventilation group were larger than that of the non-invasive ventilation group,and the difference was statistically significant（ P < 0. 05）. Conclusion Excess syndrome and deficiency syndrome are the majority in the non-invasive ventilation group,and especially lung qi deficiency is the most; while,intermingled deficiency and excess syndrome is the majority in the invasive ventilation group,and lung and spleen qi deficiency and phlegm covering the orifices are the most. Those with the scores above 22 may consider using invasive ventilation,while those with the scores under 15 choosing non-invasive ventilation.