The paper focuses on analysis of temporal change in the area and other parameters of Lumding Tsho lake in Dudh-Koshi basin, which is reported as potentially dangerous lake. The methods adopted include direct field observations, interpretation of Imageries and Topographic maps of various dates and analyses by GIS to detect temporal changes and calculate dimensions of the lake. The area of lake increased from 10.36 to 97.61ha and length from 620 to 2140 m from 1963 to 2009 with the rate of change in area of 5% and MAI of 1.9 ha. Expanding area of the lake has indicated that it could create potential threat in future. However, dam observations like the existence of level of water and underside dam at the same level and long tail of end-moraine and additional dam make it strong. Hence, the lake is unlikely to burst in the near future posing danger. Thus, a detailed study and regular monitoring of the lake are recommended.