As mobile technologies become widespread, teachers and students will be increasingly mobile, using more portable devices and interacting with computationally-enhanced learning environment. In this paper, we proposed a personalized knowledge service framework for mobile learning to adapt knowledge to different learners, leveraging Semantic Web Services in support of context awareness. This includes modeling sources of context information as web services that can be automatically discovered and accessed by knowledge adaptation engine, which assist the mobile learners with different sets of learning tasks. The paper then described the decision algorithm based on the requirements process and described the system implementation.