The book addressed the causes, historical background and impact of tsunami which happened on December 26, 2004 on the several countries which are located in the adjacent of Indian Ocean. This book is an attempt to analysis the relationship of earthquake and tsunami which occurred unexpectedly. Efforts have been made to understand the behavior of this environmental disturbances and suitable condition for formation of tsunami in the Indian Ocean and its impact on South and South-East Asian countries. The study has been carried out under the framework of GIS where used Arc View 3.3 and Arc GIS 9.2 and ERDAS IMAGINE 8.4 to find out the formation area and tracks of tsunami over the Indian Ocean. The analysis focuses on accounting of damages and loss to human lives and properties, fishing equipment’s, aquaculture projects and also impact on community well-being, including loss of sources of income and enterprises. This book also discourses the impact of tsunami in South and South-East Asian countries and assesses the management and mitigation system and put forward some recommendation to reduce that devastating loss.