BACKGROUND: Annexins (including annexin A1 and annexin A2) are important proteins which have some roles in organisms such as intracellular signal conduction, membrane cellular skeletal connection, cellular proliferation and differentiation, especially inhibitory function in inflammation processing. Pasteurella multocida is the most common bacterial pathogen and has high prevalence in pneumonia. Objectives: This study was aimed to determine experimentally annexin A1 and annexin A2 in the serum of calves affected by Pasteurella multocida pneumonia. Methods: In this research, 10 male calves (2 - 4 months) were allocated to two equal groups, one group as the case: 300 ml in dilution 2×109 CFU Pasteurella multocida bacteria and the other as control group: 300 ml normal saline inoculated by special lavage catheter through oral to trachea. Clinical scores were recorded based on available tables. In treatment group, about 18 to 24 hours after inoculation and synchronous with observation clinical signs changes, bronchoalveolar lavage for cytology and bacteriology examination were done of fluids results from washing. Blood sampling was taken from calves jugular vein in both groups then blood serums were examined by using ELISA kits. Results: The rates of annexin A1 and annexin A2  in blood serum of treatment group showed significant increase (using independent t test) compared to control group (p<0.05). Conclusions: It seems these annexins (annexin A1 and annexin A2) can be used as important biomarkers in blood serum to diagnose inflammation processes such as pneumonia.