Tourism/recreation is an important category of cultural ecosystem services. Selecting Three Parallel Rivers Region as study area, this research assessed the existing and potential tourism/recreation ecosystem services from two aspects of the tourism/recreation potential and opportunity. The amounts of tourism/recreation ecosystem services were classified into five levels, and six indicators were used in the assessment, including landscape diversity, naturalness, rivers and lakes elements, scenic spots levels, accessibility and serving infrastructure. The results showed that both tourism/recreation potential and opportunity had significant impacts on the amounts of such ecosystem services. The spatial distributions between the tourism/recreation potential and opportunity were not well matched. The areas with high tourism/recreation potential accounted for 17.09% of the total study area, mostly being located in Nujiang prefecture, Dali prefecture, Deqin county, Lijiang ancient town and some areas of Yulong county. The areas with extremely low tourism/recreation opportunity were mainly distributed in Gongshan county, Deqin county and the northern region of Shangri-La, accounting for 10.06% of the study area. About 17.64% of the study area that had high levels of potential tourism/recreation ecosystem services were concentrated in Dali prefecture, Lijiang ancient town, Yulong county and some areas of Shangri-La. Most of the scenic spots with high tourism/recreation potential also had high amounts of existing ecosystem services. The scenic spots at the fourth and fifth service levels accounted for 44.68% of the total. They were concentrated in Dali prefecture, Yulong county, Shangri-La and Deqin county, and had a quite similar spatial pattern with the high levels of potential tourism/recreation ecosystem services. This indicated that the development of existing tourism/recreation services matched the natural conditions to some degree.