The doctrine of sunyata (emptiness) is the fundamental doctrine of Mahayana Buddhism. It paves the way for the both Madhyamaka and early Yogacara philosophies, and functions as a vital link which connects the whole of Mahayana Buddhist doctrinal thought. The Madhyamaka philosophy focuses on the philosophy of absolute emptiness which is a natural outcome of the doctrine of dependent origination (pratityasamutpada), empty of self nature of all phenomena. This notion, however, was brought to completion by the Yogacara with various positive theories such as the theory of consciousness-only (cittamatra), the three-nature theory (trisvabhava), etc. The research, moreover, attempts to elaborate the close relationship between these two schools in terms of the notion sunyata. They only argue the same doctrine of emptiness through their own terminologies. The research finally emphasizes the importance of right understanding of emptiness in progressing insight meditation on emptiness for attaining the highest enlightenment, Buddhahood.