The etiological impacts in primary carcinama of the liver among .Koreans differ from those is western countries as with its high incidence anri unusual association of preneoplastic conditiens, requiring an unique criterion-setting on histopathologic description and the aaeurate prevalence rate in each types and groups. Three hundred and two cases of primary malignant epithelial neoplasm of the liver were reclasaified in accordance with two-way specifications of histological growth patterns and cytological features, and the mode of growth in each of hepatocellular carcinoma wae discussed along with degree of differentiation, atromal reaction and functional expressions. Of 302 cases, hepatocellular carcinoma(HCC) comprised 87. 4%, cholangiocarcinoma (CC) 8.3%, combined carcinoma L3% and hepatoblastoma 3.0%, respectively. The male to female ratio waa 4. 8: 1 in overall ceses. Trabecular structure was essumed as a baaic histological growth pattern of HCC. from which all other variants developed by imbalance of growth rate between neop1astic hepatocytes and stramal reactian. purther subolassification of HCC was rationalized by cytologlc features of neoplaetic celle, raaging from cirrhotomimetic (84.1%) to pleomorphic (9.5%), clear cell (5. 7%) and spindle cell groups (0. 7%) in order af fnquency. The combination of these two criteria seems to provide more accurate and sufficient informations not only for morpholagical differential diagnoeis but also in evaluation of clinical prognosis in HCC. Eight percent of clear cell group wae found to be a variant by excessive accumulation of glycogen within the reoplastic cells, and the rest by neutral fatty suhstance. which required careful seatch for differential diagnoais -from aon-neoplaatic steatosis. Degree af cellular differentiation was indirectly reflected by cytological features, and its grading eeemed an unreliable indicator for clinical correlatioa because of ita subjectivity of criterion-setting and limited reproducibility. Functional expressian of HCC such as bile production, glycogen storage and teatosis was the secondary morphological manifestation of differentiated neoplastic hepatocytes with limited significance as a separate heading for biological behavior. Three types of intracellular inclusiona were presented. and their morphogeneais and etiolagical implication were emphasized. Hyaline globule was found in 10.3% of HCC, and was discussed along the line of relationship to alpha-1-antitrypsin and HBsAg. A case of so-called easinophilic hepatocelJ,ular carcinoma with lamellar fibrosis, the first proven case in Korea, was included in this study. and histological characteristics and frequency of cholangiocarcinomas and hepatoblastamas were analized. It seems appropriate that the above two-way specification is essential and valid for the determination of carcinogenesis snd prognosis in HCC especially in Korea, and should be applied for a baseline criterion in interpretation of statistical data.