Abstract: The Ca-bentonite clay produced in Ningming county of Guangxi was used as a raw material to make a preservative liquid by mixing with distilled water in a ratio of 1 ∶ 15. The bentonite preservation liquid was prepared using the ultrasonic instrument to treat for 75 min at 600 W ultrasonic power. Two kinds of preservation liquid were coated respectively on the surfaces of mangos, the experimental mangoes were stored at room temperature by measuring various physiological parameters to study preservation effect.The results showed ultrasonic modified bentonite preservation liquid had a better preservation effect, it had a good performance in the inhibition of peel turning yellow, flesh decay and quality loss. At the same time, it could significantly reduce the respiration of the mango, the degradation rates of titratable acid and vitamin C and the accumulation rate of soluble sugar. The flesh of treated mango had a good taste and their heavy metal content was within the limit of the national standards.