With the global positioning function, mobile learning technology extends the capacity of modern learning to fulfill location-based learning for learners to learn everywhere contextually. This study developed a digital interactive geographic map (iMap) with GPS function to support location-based contextualized EFL learning. Four classes of ninth-graders from a junior high school voluntarily participated in the 2-session 70-min learning activities using tablet PCs. Two experimental groups (non-caption vs. English-caption) were implemented, and the effects of caption and gender on learning performance and motivation were examined. The results showed that the caption*gender interaction was significant on learning performance, and the male non-caption group outperformed the male English-caption group, while the female learners in both groups performed equally. As for motivation, the participants demonstrated positive motivation in all aspects (i.e., self-efficacy, proactive learning, learning value, achievement goal and environmental incentive), and the non-caption group showed higher degrees of motivation in self-efficacy, learning value and environmental incentive than the English-caption group, while the gender effect was non-significant on these motivation aspects. Furthermore, the caption*gender interaction on proactive learning and achievement goal indicated that captions tended to interfere male learners' learning intention and sense of achievement, suggesting that the adaption of learning strategies to individual traits and gender differences is imperative. This research extends the investigation on issues concerning the application of iMap-enhanced contextualized learning to the research field of technology-enhanced language learning, and the findings further support the argument that contextualized learning induces high motivation and assists learners in language comprehension and application. Copyright © 2019 Published by Elsevier Ltd.