In this study, a collaborative annotation approach based on Linked Data technology (CAALDT) is proposed for improving students' learning. An experiment was conducted to evaluate the effectiveness of the proposed approach by comparing the learning performance of the students who learned with CAALDT and those who learned with the conventional collaborative annotation approach. From the experimental results, it was found that the proposed approach improved not only the students' learning achievements, but also their learning motivation and attitudes. Moreover, it was found that the CAALDT approach provided more challenging learning opportunities that enabled students to review the annotations of their peers or teacher as well as to expose their annotations as Linked Data, therefore contributing to the expansion of the learning contents.