Rail transit is the most effective way to solve the urban traffic problem. However, due to the large initial investment and plenty of engineering materials it needs, it is valuable to study the problem on the return of the investment benefit. The paper first proves that the benefit of the construction of the rail transit will be the increased value of the land along the rail, and the benefit can be considered as the difference between the land prices before and after the opening of the rail. Secondly, based on this theory, by taking Dalian LRT NO.3 as the case study, a practical Hedonic Approach model is developed. And then, the influence of the being planned Dalian LRT NO.4 on the land price is calculated.