According to the Agricultural Encyclopedia, the differences between Siam grapefruit in Thailand and Vietnamese grapefruit are as follows: Appearance: Siam grapefruit in Thailand is usually round or slightly oval in appearance, with thick peel and light yellow or orange in color. The appearance and shape of Vietnamese grapefruit are similar to those of Siam grapefruit in Thailand, but the skin is thin and the color is usually orange or red-orange. Taste: The pulp of Siam grapefruit in Thailand has a delicate taste, high sweetness, low acidity and a certain bitterness. The pulp of Vietnamese grapefruit has rough taste, low sweetness, high acidity and no bitterness. Origin: Siam grapefruit in Thailand is mainly produced in Thailand, and Vietnamese grapefruit is mainly produced in Vietnam. Therefore, their origin and growing environment are different, which also affects their taste and quality.