The relationship between the cell features of central type early lung cancer and the degree of invasion to the bronchial wall was investigated. Bronchial brushing specimens were obtained from 19 cases of central type early lung cancer preoperatively and the resected specimens were pathologically examined. The cell features were classified into three types: Type I: low grade atypia without increased nuclear chromatin, Type II: moderate grade atypia with increased chromatin and Type III: high grade atypia with irregular shaped nucleus and increased chromatin. The expression of Type I cells was significant in cases of carcinoma in situ or microinvasion and Type II and III cells were observed more frequently in cases with extramuscular bronchial wall invasion. The cell features as well as endoscopic findings can provide a basis for the more precise staging of early stage lung cancer and the determination of therapeutic strategy.