Textbooks from Hong Kong are widely used in Chinese medium secondary schools in Macao, but they sometimes do not perform well in arousing students interests and fulfilling students’ learning needs. As a teacher in a Chinese-medium secondary school, I have found it necessary to provide students with adapted or supplementary materials to better meet their needs and interests. In this materials design research project, materials were selected to supplement particular units in the (required) textbook. Next, teaching materials were developed to provide support to students, especially when listening and reading. The materials were critically reviewed and revised, pilot tested with a small group of students, and then field-tested with 208 students in a Chinese medium secondary school. Students’ responses to the supplementary materials were assessed via questionnaire evaluation and informal discussions. The questionnaire evaluation occurred twice, once midway through their use and again after completing all materials. The teacher also kept detailed field-test notes so as to improve the materials. Results showed that the supplementary materials played a positive role in facilitating students’ learning of English. Students responded that the materials helped them to learn required texts and aroused their interest in reading and listening lessons, as well as challenged them to use and understand more difficult English. According to teachers’ observations, students’ participation and attentiveness in class improved. Teachers also noticed remarkable improvement in their performance on tests and word-use. Based on this research, suggestions are given for developing and using teacher-generated materials to supplement Hong Kong textbooks in Chinese secondary schools.