Abstract: Bladder cancer is the most common malignant tumor of the urinary system, which mainly occurs in the bladder mucosa. While radical cystectomy (RC) combined with pelvic lymph node dissection (PLND) is the standard treatment for muscle-invasive bladder cancer (MIBC), the optimal range of PLND remains controversial. Several studies have shown that extended lymph node dissection (e-PLND) has more benefits than standard lymph node dissection (s-PLND). However, in recent years, some studies have found that the number of removed lymph nodes is a more important prognostic factor than the extent of lymphadenectomy. This article summarizes the research of the prognostic factors related to lymph node counts such as dissected lymph nodes, positive lymph nodes and lymph node density (LND) in recent years, and looks forward to establishing a model that can accurately predict the risk of lymphatic metastasis in patients with bladder cancer.