[Objective] The differentiation aud mechauism of acid buffering capacity of typical soils in Hainan province under different soil types and laud use patterns were studied to provide theoretical basis for rational utilization and management of acidified soils in Hainan province. [ Method] In the summer of 2019, 33 sites in Hainau province were selected to collect the main types of soil ( latosol, latosolic red soil, yellow soil, dry red soil, coastal sandy and paddy soil) under typical vegetation types ( dry land, paddy field, forest land and garden land), and their acid buffering properties were studied. [Result] The acid buffering capacity of typical soils in Hainan province ranged from 3. 17 to 27. 70 mmoVkg, with an average value of 9. 01 mmoVkg. The tested soils were sensitive to acid. Under different land use patterns, the soil acid buffering capacity ( 12. 14 mmoVkg) of garden land was significantly higher than that of forest land, paddy field and dry land. Under different soil types, the acid buffering capacity of yellow soil ( 17. 13 mmoVkg) was significantly higher than that of latosol, lateritic red soil, dry red soil, coastal aeolian sandy soil and paddy soil. The acid buffering capacity of typical soils in Hainan province was significantly positively correlated with cation exchange capacity, specific surface area, clay content and silt content ( P < 0. 01), and significantly positively correlated with organic matter content, total exchangeable base and base saturation ( P < 0. 05). In addition, soil acid buffer capacity was significantly negatively correlated with pH ( H2 0) and sand content ( P < 0. 01), and significantly negatively correlated with exchangeable hydrogen ( P < 0. 05). There was one grade of slightly susceptible to acid damage in the tested soil, accounting for 3. 0%. There were 2 highly vulnerable soil grades, accounting for 6. 0%. There were 30 acid-vulnerable soils, accounting for 91. 0%. [Conclusion] The acid buffering capacity of garden soil is determined by cation exchange capacity under different land use patterns in Hainan province. The acid buffering capacity of dryland and woodland soils is determined by specific surface area, cation exchange capacity and base saturation. The acid sensitivity of paddy soil is determined by organic matter content Among different soil types, the acid buffering capacity of yellow soil is most affected by specific surface area The acid buffering properties of latosol and latosolic red soil are determined by the specific surface area Dry red soil is determined by cation exchange capacity; Coastal sandy soil is determined by pH ( H2 0) ; Paddy soil is determined by organic matter content. In the future agricultural production, the rational application of chemical fertilizers, the application of organic fertilizers or the use of soil acid regulators are conducive to improving soil acid buffering capacity and providing a good environment for agricultural production [ABSTRACT FROM AUTHOR]