With advance of diagnostic imaging technics, the detection rate of small hepatocellular carcinoma (HCC) has become much increased, but the questions whether the growth pattern and histologic nature of the HCC keep maintain the original gross and microscopic features with its advancement of tumor size remain still unclear. We reviewed 39 surgically resected hepatocellular carcinomas(HCCs) with a tumor size less than or equal to 3 cm in diameter(s-HCC), and their gross and microscopic features were compared with the HCCs bigger than 3 cm (i-HCC, 199 cases). Single nodular type(SN) was the most common gross type(60%) in s-HCCs, and was followed by single nodular type with perinodular extension(SNPE; 15.4%), multinodular-discrete type(10.3%) and multinodular-confluent type(5.1%). These figures contrasted to SNPE(42.2%) and SN(20.6%) in the i-HCCs. Of the 39 s-HCCs, 25 cases(64.1%) were encapsulated, and 14 cases(36%) demonstrated intratumoral fibrous septations, being contrasted to the i-HCCs in which fibrous septa formation was mord prominent but complete capsule formation was found only in 40.2% of the larger ones. Microscopically, the trabecular type was the most frequent one(53.9%), and increased with their size while the compact type transformed into trabecular one. Thirty three cases(84.6%) were associated with macronodular cirrhosis. Seropositivity for HBsAg was found in 26 cases(66.6%), and high serum alpha-fetoprotein level over 500 IU/L was found in 15 s-HCC cases(38.4%), while 53.3% in i-HCC. The above results suggest that HCCs change their pathologic features by increase of their size, and a comparison of the details with regard to the possible mechanisms involved is discussed.