18534 Background: The Clinicopathologic features of malignant lymphomas vary to geography and differ to age. The goal of this study was to find the implication of distinction from biology, clinical features and treatment outcome of malignant lymphoma in childhood and young adult. Methods: We analysed the clinical features including age, gender, histologic type, and treatment outcome of 294 children and young adults during 13-year period (from May 1993 to November 2005) in Samsung medical center and compared our study to all age group and western childhood and adolescence group on clinical features or treatment outcome in malignant lymphoma. Results: Median age at diagnosis was 20.7 years (range: 0.1–30.1 years). Male to female ratio was 1.37:1, Of 294 cases, there were 248 cases of non-hodgkin’s lymphoma (NHL) (84.3%) and 44 cases of hodgkin’s disease (HD) (15%). This rate was significantly different to rate of all age group (HD= 5.3%) (p=0.001). Of 248 cases of non-hodgkin’s lymphoma, 134 cases (54.0%) were B-lineage and 113 cases (45.6%) were T- or NK-cell lineage. Our study group had higher rates of T- or NK-cell NHL compared to all age group (p=0.001) and western group (p=0.001). Among 248 cases of NHL, the most common histologic type was diffuse large cell lymphoma (DLBL) in our study group. Burkitt’s lymphoma (BL) was the most common histologic types in Western study group. 5-year survival rate (5YSR) was 80.4% and was superior for BL and was inferior for NK/T cell lymphoma. However male T-LBL patients had better outcome in western study group. NHL and T-cell NHL had significantly worse outcomes than HD and B-cell NHL (p=0.049, 0.001, respectively). Comparing age-groups 0–10, 10–20 and 20–30, 5YSR was inferior for the oldest patients only in NHL-, T-cell NHL- and T-cell LBL-groups. Conclusions: Our study suggested environmental and genetic factor was associated with the development of malignant lymphoma. No significant financial relationships to disclose.