In this paper, we present an adaptive mobile learning system that helps users study learning materials anytime anywhere with handheld computers such as PDAs. The theme of this research is to demonstrate the synergetic effects of mobility and adaptivity that are contextualized in a learning environment. Our system considers the information about the cognitive load that a learner is experiencing and learning contents are adaptively presented based on the cognitive and competency attributes of learners. We experimented our system against elementary school students and the results indicated that not only mobility made it possible for learners to study learning materials conveniently, but adaptively providing contents to users based on their cognitive traits enhanced the learning process greatly.