Lake Tolire, located in West Ternate District, Ternate City, is a volcanic lake that serves as a conservation area, water resource, and tourist destination. The rapid development of tourism, including infrastructure expansion, residential growth, and tourism facilities, is suspected of contributing to environmental degradation in the lake area. This study aims to analyze the development of tourism in the Lake Tolire area, identify forms of environmental degradation, examine the contributing factors, and measure the effect of tourism development on environmental damage. A quantitative approach with a survey method was employed. Primary data were collected through field observations, interviews, and questionnaires distributed to communities surrounding Lake Tolire, while secondary data were obtained from documentation, literature, and relevant institutions. Data were analyzed using validity and reliability tests, simple linear regression, the t-test, and the coefficient of determination (R²). The results indicate that tourism development has a significant effect on environmental degradation in the Lake Tolire area. Increasing tourism activities and the expansion of tourism facilities, which are not supported by adequate environmental management, have led to higher volumes of solid waste, vegetation disturbance, and declining environmental quality. Nevertheless, tourism development has also generated positive economic impacts by increasing local income and supporting the growth of small businesses. The study concludes that sustainable tourism principles should be implemented through effective environmental management, enhanced public and visitor awareness, and stricter supervision of development activities to ensure a balance between economic benefits and environmental conservation