Recent advances in mobile and wireless communication technologies have enabled various new learning approaches which situate students in environments that combine real-world and digital-world learning resources; moreover, students are allowed to share knowledge or experiences with others during the learning process. Although such an approach seems to be promising and innovative, researchers have indicated several problems when applying it to practical applications, in particular, the lack of proper strategies or tools to assist the students to learn collaboratively in such a learning scenario with abundant content. Students might feel interested when using the mobile devices to learn; however, without proper assistance or guidance, their learning achievements are usually disappointing. To cope with this problem, this study proposes a concept map-oriented Mindtool for collaborative ubiquitous learning. Experimental results from a natural science course in an elementary school show that this approach not only enhances learning motivation but also improves the learning achievements of the students.