In order to make successful oral cancer treatment, we need to understand about tumor biology and effective chemotherapeutic agents. To achieve these studies, it is necessary to develope a proper in-vivo model. Therefore the author will make try to develop more improved animal model of more applicable in various method of cancer study. In this study, the author induced in-vivo tumorigenesis in nude mice by $YD-10B_{mod}$ cell line used by YD-10B cell line originated from oral tongue squamous cell carcinoma and observed tumor formations and invasiveness of surrounding tissue, and found some results as follows : 1. The experimental group($YD-10B_{mod}$, subcutaneous injection) produced tumors 13 out of 15 mice, while the control group produced none of 5 mice. 2. The inoculation of $1{ imes}10^6$cells/mouse produced tumors 3 out of 5 mice and inoculation of $1{ imes}10^7$cells/mouse, $2{ imes}10^7$cells/mouse produced tumors in every 5 mice. 3. In the histopathologic studies, the inoculation of $1{ imes}10^6$cells/mouse group showed the characteristic features of well-differentiated squamous cell carcinoma and demarcated expansile growth, while the inoculation of $1{ imes}10^7$cells/mouse, $2{ imes}10^7$cells/mouse group showed the expansile growth with partial central necrosis and invasive growth to surrounding fat & connective tissue. These findings suggest that atopic xenograft of $YD-10B_{mod}$ cell line in nude mice has a improved productivity of tumors, produced tumors showed the characteristics feature of human tumor and invasive growth to surrounding tissue in histopathologic appearance. These atopic nude mouse model of tongue carcinoma might assist in studying oral cancer biology and effective choice of chemotherapeutic agents.