With the rise of low-carbon economy, more and more investors understand and accept the concept of sustainable development, some investors have gradually shifted business focus to green buildings, but most are still on the sidelines. For investors, the most important consideration in their decision-making is the project's future benefits. The main aim of this paper is to identify incremental return on incremental costs of green buildings from the real estate investor’s perspective by analyzing a green residential building project. Based on the detailed analysis of incremental costs and benefits of the green building, the paper obtains the incremental investment rate of return using incremental analysis method. It certifies that there is a large benefit space for the developers to invest in green buildings.