AbstractDespite increasing scholarly attention on L2 motivational changes, little is known about learners’ L2 motivational changes in a blended English learning environment and their relationship with need satisfaction and need frustration. Drawing on self‐determination theory, this study investigated how a blended English learning environment satisfied and frustrated 15 EFL (English as a Foreign Language) learners’ basic needs and the relationship between basic needs and motivational changes. Data were collected via questionnaire responses, semi‐structured interviews, and learning records. Thematic analysis revealed that learners exhibited five profiles of motivational changes, with “remaining autonomously motivated” and “changing from controlled to autonomous motivation” as two major types. In addition, the learners’ need satisfaction and need frustration exerted both independent and joint impacts on motivational changes. The joint effect exhibited variation between learners depending on need categories and need strength. Theoretically, the study extends self‐determination theory by adding the need for novelty to the original tripartite taxonomy of basic needs. In addition, the study provides empirical evidence for the debate on the independent and interaction effects regarding the roles of need satisfaction and need frustration. Pedagogical implications are proposed regarding the design of blended English courses.