Abstract:Fresh Chinese yam （Dioscorea oppositifolia L.） is highly perishable with short storage periods. In recent years， fruit and vegetable drying technology has developed rapidly， which is an important means to extend the Chinese yam processing industry chain. To improve the drying rate and reduce the nutrient loss during the drying process， fresh Chinese yam was treated with ultrasonic-assisted osmotic pretreatment of sucrose solution combined with hot-air drying， and the quality change of Chinese yam chips was analyzed by orthogonal partial least square method. The ultrasonic treatment conditions with the highest comprehensive score were ultrasonic frequency of 25 kHz， ultrasonic power of 270 W， and ultrasonic time of 30 min. The results showed that the color and texture of Chinese yam chips in ultrasonic groups were improved compared with those in the blank group， and the contents of protein and reducing sugar were also significantly increased. Compared with the ultrasonic power group， the ultrasonic frequency group had higher protein content， but lower hardness and water activity. Compared with the ultrasonic time group， the ultrasonic frequency group has higher protein content， but lower contents of reducing sugar， L* value， and water activity. To sum up， ultrasonic-assisted osmotic pretreatment combined with hot-air drying can significantly improve the quality of Chinese yam chips.