Some surface electrochemical properties of soils, including plio value, adsorption of K⁺ and Cl^- ions, degree of dissociation of K⁺ ions, bonding energy of K⁺ ions with the soil, and potassium hydroxide potential were investigated. Three pairs of soil samples, each with a paddy soil and its parent soil, representing different soil types, were aced for the study. One paddy soil was derived from latosol with more positive charge, one was derived from red earth, and another was derived from yellow-brown earth with more permanent negative charge and very little positive charge. The results showed that the surface electroehemioal properties were different in different types of paddy soil. The paddy soil derived from latosol contains less free iron oxides than its parent sail due to their removal by reductive eluviation during the development of paddy soil. This may result in the decrease in positive charge and inerease in the proportion of negative charge, hence the surface electrochemical properties of the paddy soil are remarkably different from its parent soil. The surface electro-chemical properties of paddy soils derived from yellow-brown earth and red earth showed no remarkable change during their development.