This research explores the relationships between self-directed learning readiness and transformative learning theory (TLT) reflected by the Constructivist Internet-based Learning Environment Scale (CILES). A questionnaire survey about adult learner's perceptions of Internet-based learning was administered to adults enrolled in classes in community colleges in Taiwan. A total of 593 valid questionnaires were used for the structural equation modeling analysis. The findings confirmed a second-order hierarchical factor relationship of TLT (technical, dialectical and emancipatory learning interests) from CILES. Moreover, the three domains of learning interests of transformative learning were proved to have a developmental relationship, moderated by the readiness of self-directed learning for adult learners in Internet-based learning.