A high-integrated duplexer and a fabrication method thereof. The duplexer has a first filter to pass a signal of a transmitted frequency band, a second filter to pass a signal of a received frequency band, an embedded PCB having the first and second filters bonded on a certain area of a surface of an upper side in a predetermined distance from each other, and an isolation part to prevent a signal interference between the first and second filters, and a packaging substrate to package the entire upper side of the embedded PCB so that the packaging substrate is located above and separated from the first and second filters by a predetermined distance. The fabricated high-integrated duplexer has a small size and high performance.