Abstract
In order to create better criteria for different grades of superficial bladder tumor, the WHO and ISUOP develop a new classification in 1998, which was modified in 2004. Although the new classification might be more reproducible, it has not yet been widely accepted. The low risk groups include patients with single Ta, G1, ≤3cm diameter tumors. This group has high recurrence and low progression rates. The standard treatment is the complete resection and postoperative single immediate instillation of whatever chemotherapy agent should be considered.