The soil classification of Thailand is based on the American soil taxonomy, which is divided into 10 major soil classes. Because Thailand is located in the tropical monsoon and tropical rain forest climate zone, there is no arid soil class, and the other nine soil classes are distributed. Among the nine soil groups, the most widely distributed soil group in Thailand is the old mature soil, among which the moist old soil, semi humid old soil and wet mature soil are the most common; the second is the leaching soil, which is mainly distributed in the north central plain and central plain of Thailand; the original soil is also widely distributed in Thailand, suitable for planting rice; other soil types, such as Neogene soil, denatured soil, soft soil, lime soil, oxidized soil, etc Organic soil and other soil types are distributed in Thailand. Affected by the climate of Thailand, the soil types are mainly wet and humid.