Abstract: OBJECTIVE To observe and analyze the change situation of microcirculation state and pulmonary surfactant protein in patients with carbon monoxide poisoning complicated with pulmonary infection,in order to provide guidance basis for prevention and control of pulmonary infection in patients. METHODS A total of 46 patients with carbon monoxide poisoning complicated with pulmonary infection in our hospital from May 2013 to Dec. 2015 were selected as group A,another 46 patients with carbon monoxide poisoning at the same time but without pulmonary infection as group B,another 46 healthy people as group C. The nailfold microcirculation weighted integral and serum pulmonary surfactant protein levels of three groups were compared. Those indexes of patients in group A and group B with different degrees of carbon monoxide poisoning were compared too. RESULTS The blood flow pattern integral in nailfold microcirculation weighted integral,loop morphology integral,dirca loop state integral and total integral of group A were respectively (1.99±0.16),(1.05±0.11),(0.75±0.10)and (3.76±0.22),and they were all significantly higher than group B(1.35±0.12),(0.67±0.07),(0.59±0.08) and (2.20±0.17) , group C (0.76±0.08),(0.35±0.04),(0.40±0.05)and (1.35±0.11) (P＜0.05). The serum pulmonary surfactant protein level in group A was higher than that in group B and group C,and the results of group B was higher than group C,and the detection levels of group A with mild,moderate and severe of poisoning were all higher than those of group B (P＜0.05). CONCLUSION The microcirculation state and pulmonary surfactant protein of patients with carbon monoxide poisoning complicated with pulmonary infection are relatively worse,and pulmonary infection actually makes the abnormal status even worse, so the prevention and control of pulmonary infection in those patients should be paid more attention.