The traditional approach studies metaphor, metonymy and synecdoche as individual linguistic expressions or rhetoric devices, which seems a little difficult to distinguish them from each other clearly. The cognitive linguistic view provides new perspectives and proofs for the study of them. According to cognitive linguists, they are a common cognitive phenomenon of human beings, far from being a mere matter of ornament to language. The article aims at pointing out the differences among them from a cognitive perspective. The comparison of them from a cognitive linguistic view can help the learners to master them more easily.
