Abstract: A novel ¹⁸F^- labeled prostate specific membrane antigen ¹⁸F-JK-PSMA-7 was synthesized, its biodistribution in mice was determined and its preliminary PET/CT imaging was studied. ¹⁸F-JK-PSMA-7 was synthesized through 4 steps of nucleophilic substitution、acid hydrolysis、high performance liquid chromatography separation and solid phase extraction. Its quality and in vitro stability were determined, and lipid-water partition coefficient was calculated. in addition, its biological safety and biological distribution characteristics were evaluated through animal experiments. PET/CT imaging was performed on 1 healthy volunteer and 3 prostate cancer patients. The synthesis time of ¹⁸F-JK-PSMA-7 was 45 min, and the synthesis yield was (31.0±2.5)% (without attenuation correction, n=3), the radiochemical purity was greater than 99%, and other quality control results met the clinical requirements. In vitro stability of the drug was good, and the radiochemical purity was still greater than 95% after 3 half-lives at room temperature, its lipid-water partition coefficient logP was calculated to be equal to -3.56±0.13. Biodistribution experiments of drug showed that it had good stability in vivo, and it was barely concentrated in muscle and bone at the time points measured, but the drug was highly concentrated in the bladder, which proved that it was metabolized by the urinary system. PET/CT imaging of 1 healthy volunteer and 3 prostate cancer patients showed that 1 healthy volunteer had physiologically high uptake mainly in salivary gland, lacrimal gland, submandibular gland, liver, spleen, intestine, bladder. ¹⁸F-JK-PSMA-7 was concentrated in Prostate lesions and metastases of 3 patients with prostate cancer with the maximum standard uptake value (SUVmax) of 54.82. It can be seen that the new prostate-specific membrane antigen imaging agent ¹⁸F-JK-PSMA-7 has high synthetic yield、high radiochemical purity and stable quality, and has the potential to become a new drug for the diagnosis of prostate cancer.