【Objective】 Timely and accurate measurement of in situ soil pH is crucial for agricultural production and soil pollution remediation. However, the long-term stability of pH electrodes in soil monitoring remains a challenge. 【Method】 This study evaluated the effectiveness of three types of pH electrodes: spherical glass combined pH electrodes, conical glass combined pH electrodes, and an antimony (Sb) metal pH electrode, for monitoring the pH of acidic Ultisol over 350 days. Additionally, in situ soil pH values from incubated soil were measured using an extra conical glass combined pH electrode. 【Result】 The slopes of all three electrode types showed minimal changes before and after embedding in soil. The slope ranges for the spherical glass, conical glass, and Sb metal electrodes were –58.07 to –60.30, –50.79 to –55.65, and -34.38 to –35.24 mV/pH, respectively, with the spherical glass electrode showing the highest sensitivity. Correlation analysis between in situ monitored pH values and those measured with the extra conical glass electrode revealed significant correlations for the spherical glass and Sb metal electrodes (P<0.01), with correlation coefficients (r) of 0.74, 0.75, 0.56, and 0.80, respectively. In contrast, no significant correlation was observed between the pH values measured by the conical glass electrode and the extra electrode, with r values of –0.38 and 0.15, respectively (P>0.05). 【Conclusion】 These findings suggest that both the spherical glass and Sb metal electrodes are suitable for long-term soil pH monitoring. However, the spherical glass electrode with a protective device is recommended for short-term, high-accuracy monitoring, while the Sb metal electrode is more suited for long-term monitoring applications.