An inquiry-based ubiquitous tour system is proposed in this paper. The main concept is to use the strategy of inquiry to achieve the purposes of guiding and learning by using PDAs in a ubiquitous environment. This system has the following characteristics: the inquiry learning theory is used to design the guide activities, the provisions of clues are used to guide the inquiry activities of learners in the process of inquiry, and to use interactive learning objects to enhance motivation and learning interest, the system also uses GPS and instant messaging functions for cooperative learning. After the system is completed, a questionnaire based on the technology acceptance model is designed to assess the learning effectiveness of learners. The questionnaire includes system quality, content quality, environment quality, system mobility, perceived usefulness, perceived ease of use, and behavioral intentions to learner. There are a total of 9 hypotheses in the study questions, and a total of 17 items. The experimental results show that the research scale is highly reliable and all of the assumptions are valid.