It has been widely accepted that long-standing cases with ulcerative colitis, especially pancolitis have higher risk of complicating colitic cancer. Colitic cancer often appears as multi-focal invasive features with un-differentiated histology. Therefore, endoscopic diagnosis of precancerous or cancer associated dysplastic lesions. Surveillance colonoscopy has preventing effects for developing colitic cancer. In western world, annual surveillance colonoscopy with multiple stepwise has been adopted. In Japan, surveillance colonoscopy with targeted biopsies assisted by chromoendoscopy and/or magnifying endoscopy has proven to be efficacious in finding such lesions.