Based on the data of the 120 layers of 6soil groups which distributed in 60 tea gardens in Wuyishan city in Fujian province, the acidic characteristics of tea garden soils in subtropical China was investigated. The results were as follows: the average soil pH of 0~20cm soil layer was 4.52, and highly acidified soil with pH lower than 4.5 accounted for 55.00% of the total samples. Meanwhile, the average soil pH of 20~40cm soil layer was 4.52, and 53.33% of the samples were lower than 4.5. The average pH of red soils, purple soils, coarse soils in tea garden were all below 4.5in 0~20cm and 20~40cm soil layers. Therefore, high acidification was a serious problem in the majority of tea garden soil in Wuyishan city. Soil exchangeable Al³⁺ and the ratio of exchangeable Al³⁺ against exchangeable acid increased proportionally to the increasing rate of exchangeable acid, while the ratio of exchangeable H⁺ against exchangeable acid has the contrary phenomena. Exchangeable Al³⁺ made up 76.67%~98.40% of exchangeable acid. The pH of tea garden soil has significantly negative correlation with exchangeable acid, exchangeable H⁺ and exchangeable Al³⁺, of which the correlation coefficients were -0.61, -0.46 and -0.59, respectively. The buffering capacity to acid and alkali decreased with the decreasing soil pH. Generally, the soil pH had significantly positive correlation with base saturation, which is mainly controlled by exchangeable Ca²⁺ and Mg²⁺. However, different soil types had different characteristics in terms of their relationships. Therefore, it reflected the complexity and diversity of tea garden soil acidity.