About 1500 high-risk subjects of esophageal cancer were found during screening by balloon cytology and all of them were examined endoscopically. Among them, 120 were considered as having early esophageal cancer and precancerous lesions. During the examination, Lugol's solution staining was used and guiding biopsy was taken. 98 subjects with unstained lesions were found, and biopsy showed early esophageal cancer in 60 (61.2%) and moderate and severe dysplasia in 38 (38.8%). It is usually extremely difficult to detect and localize the very early esophageal mucosal and submucosal carcinoma. But endoscopic examination and using Lugol's solution staining with multiple spots biopsy from unstained area are of great assistance. Minute malignant lesions may not be overlooked.