Objective：To compare the therapeutic effects of penehyclidine hydrochloride on rat with oleic acid (OA)-induced acute lung injury (ALI) when given via inhalation and intravenous injection. Methods: Forty male Sprague-Dawley rats were randomly divided into 4 equal groups: normal control group（group Ⅰ）,ALI group（group Ⅱ）,penehyclidine hydrochloride inhalation group（group Ⅲ），and intravenous penehyclidine hydrochloride group（group Ⅳ）. The blood pressure (BP),pulmonary artery pressure (PAP),and airway pressure (Paw) were determined every 60 min during the experiment and the artery blood gas analysis and mixed venous blood gas analysis were performed. The wet to dry lung weight ratio (W/D ) and the serum concentration of tumor necrosis factor alpha (TNF-α) were determined 240 min after the experiment in each group. Results: The OA-induced increase of PAP,Paw and decrease of PaO2/FiO2 were improved in the group Ⅲ and group Ⅳ compared with those in the group Ⅱ(P<0.05 for group Ⅲ). The W/D and serum TNF-α concentration were lower in the group Ⅲ and group Ⅳ compared with those in the group Ⅱ (P<0.05 for group Ⅲ). Conclusion: Penehyclidine hydrochloride can relieve the symptoms of OA-induced ALI. Inhalation approach is more effective than intravenous injection when the same dose of penehyclidine hydrochloride is given.