Purpose: To study perfusion parameters’change of pulmonary microvascular in different severity of liver cirrhosis with GE 16 slices spiral-CT.Material and Method: Dynamic contrast-enhanced single-location sequences CT scans of the lung were obtained in 20 control subjects and 43 patients of hepatic cirrhosis (24 patients with compensated cirrhosis and 19 patients with decompensate cirrhosis). These data were processed on GE AW4.1 workstation using perfusion 3 software packages. The time-density curve (TDC) of region of interest and perfusion parameters of pulmonary microvascular such as blood flow ( BF),blood volume(BV),mean transit time(MTT)and permeability surface area product(PS)were calculated. Statistics treatment applied SPSS 11.5 software, and the result of perfusion parameters of pulmonary microvascular of each interclass took analysis of variance average (ANOVA) (two group parameters, MTT and PS, mismatched normal distribution,thus made logarithmic transformation), then the multiple comparisons was estimated using LSD test (adjusted Tamhane t test was made if heterogeneity of variance of interclass).Results: BF、BV of the pulmonary microvascular’s perfusion parameters of three group had significant difference and had statistical significance(P =0.000 and 0.000). Compared to control group and compensated cirrhosis group, the BF and BV of decompensate cirrhosis group were significantly increased, and the difference of interclass had statistical significance(BF =0.004 and 0.003; BV: P =0.004 and 0.003). But compared to control group, the BF and BV of compensated cirrhosis group had not significant difference(P =0.958 and 0.998).MTT of pulmonary microvascular’s perfusion parameters mismatched normal distribution,thus made logarithmic transformation,and the population mean of three group had significant difference (P =0.023 ) . Compared to control group and compensated cirrhosis group, the MTT of decompensate cirrhosis group were decreased, but the difference of interclass had statistical significance(P =0.013 and 0.019).PS of pulmonary microvascular’s perfusion parameters mismatched normal distribution,thus made logarithmic transformation,and the difference of interclass had not statistical significance(P =0.337).Conclusion: 1 The significantly increased of BF and BV, the decreased MTT, and the slightly increased of PS were observed in pulmonary microvascular’s perfusion parameters of three groups. In addition , the change of CT perfusion parameters was correlated to the degree of hepatic cirrhosis. 2 In hepatic cirrhosis, the change of pulmonary microvascular’s perfusion parameters,especially BF and BV, can reflect changed degree of liver cirrhosis at some extent.3 MSCT perfusion imaging of the pulmonary microvascular can get many perfusion parameters of the pulmonary microvascular in liver cirrhosis, quantity analyze the change of the pulmonary microvascular, get information of pulmonary functionology.4 MSCT perfusion imaging of the pulmonary microvascular provided a new research method for moving forward a single step to probe the rule of liver cirrhosis developing.