<p>The surface tension effects are an intrinsic property of various types of interfaces, especially in electrochemical systems. In this work, the classical deformation-independent surface elasticity model is incorporated into the Poisson-Nernst-Planck equations to construct a diffusion impedance model that accounts for surface tension effects. The derived model is used to analyze the impact of surface tension on electrochemical impedance spectroscopy, focusing on Nyquist plots, response frequencies, and impedance magnitudes. The results show that surface tension significantly affects equivalent series resistance (ESR) and diffusion impedance, especially in curved interfaces. Increasing surface tension reduces ESR and enhances low-frequency diffusion impedance, with trends differing slightly between convex and concave surfaces. Furthermore, the effects of concentrations, electric fields, and dielectric permittivities in the presence of surface tension are analyzed. This study provides a theoretical framework for integrating surface tension effects into electrochemical models and highlights their critical role in understanding interfacial phenomena.</p>