The CVM (Contingent Valuation Method) and the TCM (Travel Cost Method) are commonly used to estimate the value of environment, but both of them have some drawbacks yet to be solved. In this paper, the value of water environment in the Suwa Lake was estimated at four levels of improvement by both CVM and TCM under stated preference. The results suggest that the estimated values by the CVM include a certain amount of overestimation caused by the embedding effect. On the other hand, the relative values among the four levels by the TCM are reliable, though the absolute values are not reliable. A novel method was proposed to eliminate this overestimation by the embedding effect in the CVM using the estimated values by the TCM, and to provide more reliable estimation.