This study is intended to investigate the difference between before-trip expectation and on-site experience of visitors dining at Shihmen fresh fish restaurants in Taoyuan. It is expected that the findings can provide the operators of Shihmen fresh fish restaurants a guiding framework for implementing sustainable development. The relationships between visitors' demographic characteristics, traveling behaviors and their before-trip expectation and on-site experience were statistically explored. The Importance- Performance Analysis (IPA) was applied to analyze the level of satisfaction of the visitors with their dining experience at fresh fish restaurants. The results indicate that the cleanliness and sanitary of the dining environment, the courtesy and enthusiasm of the service staff and the diversity and tasty of the food are the three most important issues that the operators of fresh fish restaurants should continue working on. The speed of responses, the professionalism of service staff, the quality and quantity of food, the opening hours and price list are the issues that visitors were unsatisfied with and the operators of fresh fish restaurants should make resolutions for improvement. Theoretical and practical implications were also discussed.