Upper tract urothelial carcinoma (UTUC) is a rare malignant disease which accounts for 5-10% of urothelial carcinoma in the western world and 9%-30% in China. About two thirds of patients have muscle invasive disease at diagnosis. Those patients usually have poor prognosis. The 5 year cancer specific survival is \<50% for pT2/T3 and \<10% for pT4. Radical nephroureterectomy is the standardized treatment for non-metastatic high risk UTUC. However, about half patients may suffer from impaired renal function after nephroureterectomy. On the other hand, kidney sparing surgery can avoid renal function impairment, but the therapy is only recommended for few patients with low-risk disease. The treatment for urothelial carcinoma has changed rapidly in the past few years. Immune checkpoint inhibitors and novel agents such as ADCs have shown promising therapeutic effect and were approved for patients with metastatic UTUC. Meanwhile, a recent study shows that patients with high-risk disease can also receive kidney sparing surgery without compromising cancer specific survival and overall survival. This prospective, observational study aims to evaluate the prognosis of contemporary kidney sparing surgery in patients with UTUC with or without perioperative therapy in the real world.