The invention relates to the field of biotechnology and medical diagnosis, in particular to application of chromosome instable regions to preparing an agent or kit for the diagnosis of urothelium carcinoma. There are ten chromosome instable regions 3p, 3q, 5p, 7p, 7q, 8q, 9p, 9q, 17p and 17q. Samples of clinically confirmed urothelium carcinoma patients, healthy people and non-urothelium-carcinomapatients are collected, the specific chromosome instability distribution characteristics of the urothelium carcinoma are expounded by comparing chromosome abnormity conditions of the tumor patients and the contrast through whole-genome sequencing, the ten common chromosome instable regions of the urothelium carcinoma patients are disclosed, and the total carrying rate is up to 93.4%, which has great significance in the clinical diagnosis, treatment, monitoring, prognosis and evaluation of the urothelium carcinoma and provides the scientific basis for conducting early diagnosis next and formulating an individualized treatment scheme.