This study addressed the reduction-oxidation potential in paddy soil during rice-growing season and chemical properties of soil profiles in a semiarid area of Iran. Different stages of this research including field studies, laboratory analysis and interpretation of data had done by using of Excel and SPSS programs. Redox potential (Eh) and pH were measured at soil and water depths using a portable pH meter with Pt and glass electrode. The average of pH in surface horizons of all profiles before submerging was 7.57, but this average in the rice-growing season becomes 7.19. The average of cation exchange capacity of all profiles was 20.8 Cmol (+) kg-1 and the mean of calcium carbonate percent in control section depth of all soils were more than 40%. Measured values of Eh shows that Eh values in surface depths are more than subsurface layer (45 cm deep). The most Aerobic conditions in of 1-cm depth with Eh +440 mV and the most reduction conditions in 15 and 45 cm depths the Eh was +4.5 and -222 mV, respectively. The results of the date correlation analysis shows that there is a reciprocal significant relationship between times of submergence and the mean of Eh of all depths and the mean of pH in surface depths (r = - 0.600, p = 0.003, r = - 0.747, p = 0.000, respectively). Also there is a significant relationship directly between the mean Eh and the mean pH of surface depths(r = +0.897, p = 0.000).
