Objective To investigate the effect of pulmonary fibrosis model induced by bleomycin( BLM) via intratracheal injection under microscope. Methods Thirty health adult C57 BL /6 mice( female,eight weeks of age) were selected and randomly divided into control group and observation group,with 15 mice in each group. In the control group,the mice were intratracheal injected with BLM under naked eye; in the observation group,the mice were intratracheal injected with BLM under microscope. The mortality in the first ...