DescriptionSmallholders who live in the forest margin of tropical forests in developing coun- tries are the most vulnerable population, what has been aggravated due to the con- sequences of climate change. The complexity of their adaptation to climate change is growing along with the increasing importance of the tropical forests to mitigate climate change on a global scale, which has manifested in forest protection policies in developing countries. Through analyzing a case study of the Batulanteh Watershed, this dissertation examines smallholders’ livelihood under the structural constraint of forest protection policies and their vulnerability and adaptation to climate change. The dissertation addresses five goals: First, examining the rationale and the goals of smallholders’ livelihood and the government’s policy in the upper watershed and how climate change influences both conflicting parts; second, investigating smallholders’ perceived vulnerability; third, elucidating smallholders’ climate change knowledge and the role of traditional ecological knowledge for smallholders’ adaptation to cli- mate change; four, analyzing smallholders’ adaptation and the factors that influence smallholders’ adaptation to climate change; five, studying the role of adaptation to climate change policy to reduce smallholders’ vulnerability to climate change and the barrier for developing a climate change adaptation policy. This dissertation research seeks to provide new insights that reveal a more under- standing of the link between climate change policy and vulnerability and adaptation of the vulnerable population to climate change, hence providing theoretical contribu- tions to the field of Sustainable Livelihood Approach, Political Ecology, Vulnerability, Maladaptation, and Risk Perception. To guide the research inquiries, multiple meth- ods have been employed including a household survey, focus group discussions, par- ticipant observation, semi-structured and in-depth interviews, and archival research.