〔Abstract〕 Objective To explore the feasibility of constructing a programmed death receptor-1 (PD-1) molecular probe f or non-invasive micro-positron emission tomography/computed tomography (Micro-PET/CT) imaging of PD-1 protein in mouse S180 sarcoma. Methods A transgenic PD-1 C57 S180 sarcoma mouse model was established using the S180 sarcoma cell injection.Furthermore, 124I-anti-PD-1 monoclonal antibody probe was synthesized. 18.5 MBq of the 124I-anti-PD-1 probe was injected into the tail vein of transgenic PD-1 C57 mice. Subsequently, S180 sarcoma was imaged using Micro-PET/CT. Results Study successfully established a transgenic PD-1 C57 S180 sarcoma mouse model. Immunohistochemical (IHC) results showed PD-1 protein expression in S180 sarcoma. Micro-PET/CT imaging successfully visualized the PD-1 protein receptor in S180 sarcoma at different time points (20, 48, 72, and 120 h) after probe injection. Conclusion The 124I-anti-PD-1 monoclonal antibody molecular probe successfully targets the PD-1 receptor in S180 sarcoma of transgenic PD-1 C57 mice, and presents clear Micro-PET/CT immunoassay results, thus it potentially enables the non-invasive screening of patients with PD-1 positive malignant tumors.