Vocabulary usually presents one of the biggest challenges in FL learning. This book explores a new approach called the Strategy-based Constructivist Approach (SBCA) to enhance self-directed vocabulary learning. It assumes that learners should discover and construct new word knowledge actively in an authentic environment based upon their existing mental lexicon, working either by individual or through collaboration. The utilization of processing-involved and interactive vocabulary learning strategies is highlighted as a crucial component in this approach. Diversified and meaningful tasks are expected to stimulate that utilization to realize the SBCA in a basic way; and learning medium, learning processes and learning paths are the additional factors for improving that utilization to realize the SBCA effectively. For the development of a courseware package to achieve the effective realization of the SBCA, a new framework for language courseware engineering is formulated with explicitness, systematicity and practicability; new vocabulary learning processes are proposed to facilitate students’ utilization of vocabulary learning strategies in a rational way; and learning paths addressing students’ different learning styles are designed to achieve individualized learning. A vocabulary learning courseware prototype called Learning Vocabulary In Domain is ultimately developed. This book illuminates the direction of future research on vocabulary learning in FL learning.