Hainan Island is a climate change sensitive area and a fragile eco-environmental area. In recent decades, climate change and human activities have profoundly affected the eco-environmental quality of Hainan Island. However, the temporal and spatial evolution of eco-environmental quality and its response to climate change and human activities in Hainan Island in recent decades are not clear. Understanding these issues is of great significance to achieve the goal of sustainable development of Hainan Island. Based on multi-source remote sensing data, this study used Modified Remote Sensing Ecological Index (MRSEI) to explore the temporal and spatial variation characteristics of eco-environmental quality of Hainan Island from 1992 to 2015, and analyzed the response of eco-environmental quality of Hainan Island to climate change and human activities in recent 24 years. The relative importance of climate change and human activities to the eco-environmental quality was compared based on the multiple regression method of pixel scale. The results showed that:(1) the MRSEI index is applicable to large area and can be used in the evaluation of Hainan Island's eco-environmental quality in this study; (2) In the past 24 years, the eco-environmental quality of Hainan Island was a fluctuating upward trend. And in all land-use patterns, the eco-environmental quality of forest land was the highest, with the multi-year average MRSEI reaching 0.812; (3) MRSEI had a significantly positive correlation with temperature and rainfall, and a significant negative correlation with human activities, which is characterized by the nighttime light, in the coastal areas and the main urban areas of cities and counties; 4) In the past 24 years, the contribution of climate change including air temperature and precipitation variables in the evolution of MRSEI was overall higher than the impact of human activities. This work is expected to provide the quantified information on the coordination between ecological conservation and economic development in the construction process of Hainan Free Trade Port, and give scientific knowledge to formulate corresponding policies.