The developments along the Mekong River, including in Cambodia, have boomed. There were 755 dams. Of these, 537 have been completed, and 152 have been planned or proposed. Of these, 52 were under construction, and 14 have been canceled or suspended. Of these dams, 392 were hydropower, 337 were irrigation, and 26 were other types (CGIAR, 2015). Even though some officials saw economic development as a result of the hydropower dam, the negative impacts of hydropower dams were seen by many (...) local experts and NGOs. The negative impacts include reduced fishing stocks and exacerbated socio-economic issues (Asia and the Pacific Policy Society, 2022). Experts have conducted some research on ecosystems and livelihoods, but there has been a lack of studies conducted by local communities to investigate their cross-border impacts as a result of the hydropower dam, despite the fact that local communities have been facing issues as a result of the Mekong Development. The community research protocol was developed to improve local communities' understanding of their local contexts and their confidence in negotiating with decision-makers and policymakers to address and respond to their needs and the findings of studies on local planning for sustainable community development. The paper aims to guide community leaders and staff in conducting community research on transboundary impacts on fisheries resources, ecosystems, and the livelihoods of local communities using their knowledge. (shrink)