In this work, we propose and investigate a dual-tuned coaxial transmission line resonator, which can tune the two frequencies independently at the ultrahigh field of 7 Tesla. Due to the use of distributed circuit of co-axial transmission line, this new design possesses unique features, including high-frequency operation capability, high Q factors, and improved decoupling of the two nuclear channels, which enable highly sensitive detection of MR signals from both protons and heteronuclei. The successful development of this new dual-tuned RF coil technique would provide a tangible and efficient tool for ultrahigh field metabolic MR imaging. We believe that the technology proposed in this work will have a significant impact to high and ultrahigh field MRSI.