Tilapia Lake virus disease is an emerging virus that causes the death of tilapia and red tilapia fry during the first month. The virus was found to have spread throughout Thailand along the river and some water resources where fish are abundant. The characteristics of fish infected with Tilapia Lake are seen, with the virus infecting the liver and internal organs to be severely damaged, by swimming on the surface of the water, bulging eyes, swollen abdomen and red face. Therefore, surveillance of Tilapia Lake Disease must be monitored in order to reduce the spread of tilapia fry. This research will lead to sustainable disease prevention and control. The research by Assoc. Prof. Dr. Win Surachetphong, Department of Microbiology and Immunology, The Faculty of Veterinary Science of Kasetsart University. Tel. 0-2589-0058.