Bangladesh is most vulnerable to several natural disasters because the geographical setting of the country, along with the funnel shaped Bay of Bengal make it subjected to the catastrophic ravages of natural disasters. The present study area, Sundargang and Fulchari upazila of Gaibandha district is mainly stands on most activated geological region, the Tista and the Brahmaputra-Jamuna flood plain. Its physiography and river morphology contribute to recurring disasters. Normally this area is formed by temporary char land and affected by flood and river bank erosion every year. So the goal of the study is to assess the vulnerability on livelihood pattern and the adaptation mechanism of the local people to cope with natural disasters. It has been observed that social vulnerability of all the 12 unions of Fulchari and Sundargang Upazila is 0.61 and hazard vulnerability is 0.78. As well as the composite vulnerability of the study area is 0.70. Changes in the river flows and sediment transport due to multi-dimensional impacts of climate change are expected to increase the vulnerability level. These areas have not been the focus of development efforts of the public or private agencies.