The purpose of this study was to explore the effects of the digital material incorporated into Text-to- Speech system for students' English spelling. The digital material was made on the basis of the Spelling Bee vocabulary list (approximately 300 words) issued by the selected school. 21 third graders from a private bilingual school in Taiwan were selected for this study. This study employed four data collection techniques, including questionnaire, pre-test and post-test, informal observation and interview, and semi-structured individual interviews. The research results showed that the use of digital material fostered the students' English spelling ability and their self-directed learning.