Objectives: The purpose of this paper was to suggest a new diagnostic method to estimate the electrical properties at acupoints. Thus, we developed a multi-frequency bioelectrical impedance measurement system to analyze the state of bioions in body fluids, not the skin impedance at an acupoint, for various body compositions. Methods: At low frequencies, the current does not penetrate the cell membrane, and at high frequencies, the current passes through both intracellular and extracellular fluids because of a decrease in the cell membrane’s impedance. To confirm the effect of the composition of an extracellular fluid or an intracellular fluid in a segment such as an acupoint, are developed a system to detect the acupoint potential at 5, 50 and 200 KHz between two adjacent points in the areas of LU3, LU4 and LU9. Results: The detected acupoint potential decreased with increasing frequency. A correlation analysis of identical left/right acupoints showed a high correlation for three types of acupoint potentials at multiple frequencies. Moreover, we observed a low correlation at 5 KHz, which is a significant factor to be considered for the unbalanced relationship between identical acupoints. Conclusions: On the basis of a meridian theoretical point of view, we may infer the acupoint’s physiological composition by using the multi-developed frequency bioelectrical impedance measurement system.