The Ainu are an indigenous people mainly living in Hokkaido, Japan. Marriage in traditional Ainu society had distinctive characteristics shaped by long-standing customs. From a socio-anthropological perspective, this paper combines quantitative and qualitative methods to analyze documents and assess both traditional and contemporary marriage attitudes among the Ainu in Hokkaido (Japan). The goal is to understand their current situation and find solutions for preserving Ainu culture in particular and ethnic cultures in general. Findings show that due to the strong assimilation process by the Japanese, Ainu culture has been severely eroded. The Japanese government has made efforts to preserve Ainu culture, such as recognizing the Ainu as an indigenous people (2019), establishing research and cultural preservation centers, and providing financial support for Ainu communities to maintain their cultural identity. However, stronger measures are still needed to ensure the revival of Ainu culture in the modern context.