The Baoshan (first) Reservoir was constructed in 1981, to fulfill the need of the Hsinchu Science-Based Industrial Park and to underpin socioeconomic development in Hsinchu area. However, when the reservoir was built, the process of land expropriation was not as smooth as the residence expected. While the land over one meter of the reservoir was not counted into the expropriation area, 300 residents was not satisfied with the mode of handling and have kept protesting it for more than thirty years. The majority residents of this area are Hakka people, who migrated to Boshan, Hsinchu area for more than three hundred years. Being suffered from the conflicts in between the Min people and Hakka people, pluc with the indigenous people historically, the ethnic group finally settled in Hsinchu, and took Taiwan as their hometown. After the ethnic consciousness rose in 1980s in Taiwan, the Hakka ethnic group has started to gone through a series of social movements. The Hakka mostly live in the hills or margined in the edge of the city, they got easily impacted by the urban development and forced to take the side-effect of the development, such as pollution or land expropriation. The Baoshan First Reservoir event was one of these cases. This study, thus, aims to explore the cultural impact that may happen in the process of protesting the land expropriation and how residents perceive themselves regarding the ethnic identity and the relationships with other ethnic groups.