【Objective】 To perform serological screening of K antigen in Qingdao area and analyze the results. 【Methods】 From March to June 2023, 16 201 samples of patients treated in our hospital and applied for blood grouping, and 4 153 samples of blood donors sent to the clinic by Blood Transfusion Department during the same period were detected for Rh and K antigen by Ortho BioVue System Rh/K Cassette. 【Results】 A total of 18 out of 16 201 patient samples and 8 out of 4 153 blood donor samples were positive for K antigen, with the positive rate at 0.127 7%. 【Conclusion】 There was K antigen in Qingdao population, and the positive frequency of K antigen was different from previous reports. It is of great significance to construct rare blood group bank in this area and formulate reasonable blood donation and transfusion strategy for population with K antigen, so as to avoid unexpected antibody production of Kell blood group system, prevent hemolytic disease of newborn and ensure the safety of blood use.