Abstract:ABSTRACT: Methods We collected the urine samples From January 2019 to April 2020 in Inner Mongolia Baogang Hospital of 106 patients who had been using immuno-suppressants for more than 3 months after kidney transplantation surgery, and the decoy cells were screened by direct microscopic examination without staining, SM staining and S staining, which were later confirmed by the amplification of the nucleic acid of BK virus (BK)and JC virus(JC), whose infection was believed to have caused the specific morphological change of the cells. Results Among 106 patients,decoy cells were detected in 12 cases of the urine samples by direct microscopy without staining, The positive rate were 11.3%, 21 cases of the urine samples by SM staining and S staining, The positive rate were 19.8%, among which the positive rate of BKV and (or) JCV viral nucleic acid was 95.2%,6 cases were positive for BKV nucleic acid (28.6%),10 cases were positive for JCV nucleic acid(47.6%), 4 cases were positive for BKV and JCV nucleic acid(19.0%). Conclusion SM staining and S staining are simple, rapid and effective methods for detecting urinary decoy cells in the urine. It has important clinical significance in screening patients infected with human polyoma virus after kidney transplantation surgery due to long-term use of immuno-suppressants.