Abstract: In order to overcome the difficulty in measuring cross-section area and axial Young's modulus of a single carbon fiber,we develop a new method, Static Electric Resonance (SER),and correspoading instruments which can preucisely measure the two parameters of a single carbon fiber with any crow-section form by making use of the technique of contactless resonance.The paper includes a consideration of some factors that may cause error in measuring,in the hope of raising measurement precision further.