Objective:To explore the changes of immune microenvironment and prognosis of bladder cancer patients with positive urinary nuclear matrix protein 22 (NMP22).Methods:Retrospective analysis was made on 86 patients who were diagnosed with bladder cancer in Xuzhou Central Hospital from January 2019 to September 2020. All patients were tested for urinary NMP22 by colloidal gold method. The patients with positive test results were NMP22 positive group, and the patients with negative test results were NMP22 negative group. The expression of CD8, programmed cell death-ligand 1 (PD-L1), programmed cell death protein-1 (PD-1) and PanCK were detected by multiple fluorescent immunohistochemical method on the pathological tissue sections of all enrolled patients with bladder cancer after surgery. Follow-up data of enrolled patients were collected after discharge, and univariate and multivariate Cox analysis was performed on the follow-up data.Results:There were 69 patients in the NMP22 positive group and 17 patients in the NMP22 negative group. The percentage of CD8 and PD-L1 positive cells in NMP22 positive group was significantly higher than that in NMP22 negative group, and the difference was statistically significant (all P<0.05). Univariate analysis showed that tumor stage was correlated with bladder cancer progression ( HR=2.67, P=0.017). Multivariate analysis showed that positive NMP22 was significantly correlated with bladder cancer recurrence and disease progression (all P<0.05). Conclusions:The density of CD8 + T cells and PD-L1 in tumor parenchyma of urinary NMP22 positive bladder cancer patients was higher than that of NMP22 negative patients. Urinary NMP22 positive can be one of the bad prognostic factors of bladder cancer, and the patients with NMP22 positive should strengthen reexamination.