Uroepithelial carcinoma is a multi-origin malignant tumor originating from the urinary tract epithelium, including renal pelvis cancer, ureteral cancer, bladder cancer and urethral cancer, which is the most common urological tumor. Among them, uroepithelial carcinoma can be divided into non-myeloablative invasive uroepithelial carcinoma and myeloablative invasive uroepithelial carcinoma. And 10%-15% of patients with myxo-invasive uroepithelial carcinoma have metastasis at the time of diagnosis. The 5-year survival rate for high-risk patients with T3-T4 and/or N+Mo is only 25-35%. Cisplatin-containing chemotherapy regimens are sensitive to uroepithelial carcinoma, of which GC (gemcitabine and cisplatin) regimen is considered the current standard first-line treatment regimen. 72 patients with muscle-infiltrating uroepithelial carcinoma were treated with GC regimen in the Department of Urology, Beijing Friendship Hospital from September 2009 to September 2012, and achieved good results. Among the 72 patients, most of them showed obvious side effects during the first cycle of chemotherapy in 164 observed cycles. The main toxic side effect was bone marrow suppression, among which 58 (80.6%) had leukocyte suppression in the first cycle, degree I suppression: 42 (72.4%), degree II suppression 11 (19.0%), and degree III suppression 5 (8.6%). In addition, impaired hepatic and renal function was common: 11 (15.7%) had elevated ALT in the first cycle, including 1 with 255 U/l, 12 had (16.7%) elevated BUN, and 17 (23.6%) had elevated Cr, including 1 with 588-725 umol/l. In the second cycle, both myelosuppression and impaired hepatic and renal function had varying degrees of adverse effects declined. In addition, other toxic effects increased with the increase of chemotherapy cycles, including 23 gastrointestinal reactions (nausea, vomiting, constipation, loss of appetite), 11 fever with urinary tract infection, 14 significant alopecia, and 1 each tinnitus, rash, edema, erythema, visual repercussions, asthma, headache, insomnia, and ventricular premature infarction. Two of them died within 1 week after chemotherapy. The incidence of uroepithelial cancer in Western countries ranked 4th, after prostate, lung, and colorectal cancers. In terms of site of occurrence, it includes cancers of the renal pelvis and ureter occurring in the upper urinary tract and cancers of the bladder and urethra in the lower urinary tract. Unlike bladder cancer, about 60% of upper urinary tract epithelial cancers are infiltrative tumors with poor prognosis. Total cystectomy or full-length nephroureterectomy is the gold standard for the treatment of uroepithelial tumors, but for patients with high-risk tumors, postoperative local recurrence or distant metastases are the main reasons for the lack of improvement in long-term survival. 50% of patients with invasive bladder cancer already have underlying metastases before surgery. Therefore, the tumor is not a local manifestation, it is a systemic disease. Therefore, surgery cannot solve the whole problem, while adjuvant chemotherapy can make a big difference. Uroepithelial carcinoma is more sensitive to adjuvant chemotherapy, and the 2012 NCCN guidelines recommend that a cisplatin-based chemotherapy regimen should be chosen for patients with uroepithelial carcinoma. The previous chemotherapy regimen was cisplatin monotherapy, which was not effective. Since the introduction of the MVAC (methotrexate, vincristine, adriamycin, cisplatin) chemotherapy regimen, the platinum-based combination chemotherapy regimen has improved the survival benefit of patients with invasive bladder cancer compared to the platinum monotherapy regimen. However, this chemotherapy regimen is associated with greater toxicities and higher treatment-related mortality. With the introduction of gemcitabine, the GC (gemcitabine, cisplatin) regimen has gradually replaced MVAC as the first-line chemotherapy regimen for invasive uroepithelial carcinoma, and the GC regimen has significantly fewer clinical toxicities and essentially the same chemotherapeutic efficacy as the MVAC regimen. Gemcitabine is suitable for use in combination with DNA-damaging drugs because of its inherent property of inhibiting DNA replication and repair. The GC regimen is highly effective in treating uroepithelial carcinoma, and with close follow-up and timely adjuvant administration, significant toxicities can be reduced.