Abstract: Figuring out the relationship between the soil pH value and the medium/trace elements of citrus orchards in the soil-leaf-fruit system is of great significance for the acidification improvement, nutrient regulation, and fruit quality improvement in citrus orchards. In this study, 362 groups of citrus soil-leaf-fruit samples were collected and measured in six provinces of Hubei, Hunan, Jiangxi, Fujian, Guangdong and Yunnan. The characteristics of pH distribution, medium/trace element content and their relationship in citrus soils were investigated by using gray correlation, correlation and multiple linear regression analysis. The results showed that: (1)The average soil pH value of citrus orchard was 4.92 (acidic), and the coefficient of variation was 14.52%, which was a small variation. There were 213 and 92 acidic and strongly acidic citrus soil sample points, respectively, indicating that more than half (84.25%) of the soil sample points were in a state of excessive acidity, which was not conducive to the growth of citrus. (2) The content of available Fe, available Mn, available Ca, available Mg, available S, FeLeaves, MnLeaves, CuLeaves, ZnLeaves, CaLeaves, MgLeaves, BLeaves, SLeaves, FeFruits, MnFruits, CuFruits, ZnFruits, CaFruits, MgFruits, BFruits, SFruits with different soil pH gradations (highly acidic, acidity, faintly acidic, neutral, alkalinity) were significantly different (p<0.05). (3)The pH value of citrus soil had the highest correlation coefficients with the contents of MgFruits, MgLeaves and CaFruits, which were 0.850, 0.814 and 0.775, respectively, while the lowest correlation coefficients with the contents of MnFruits (0.629), CuFruits (0.627) and CuLeaves (0.624). The highest correlation coefficient between medium/trace elements in the available state of the soil and the soil pH value was available B (0.727) and the lowest was available Fe (0.670). The highest correlation coefficient between medium/trace elements in leaves and the soil pH value was MgLeaves (0.814) and the lowest was CuLeaves (0.624). The highest correlation coefficient between medium/trace elements in fruits and the soil pH value was MgFruits (0.850) and the lowest was CuFruits (0.627).(4) Prediction based on soil pH and medium/trace element content showed that MnFruits, CaFruits, and SFruits were affected by the corresponding leaf element content leading to the highest degree of explanation, 0.79, 0.56, and 0.56, respectively. In summary, there was a need for the citrus orchard soils to be scientifically rationalized to regulate soil pH and to balance the content of medium/trace element in order to improve the quality of citrus fruits.