Abstract: In order to clarify role that the ultrasonic penetration play in shortening the drying time and improving the rehydration, with the fresh letinous edodes as material, effects of ultrasonic power, ultrasonic treatment time, osmotic solution concentration on the drying time and the rehydration were investigated. Based on the above, ultrasonic penetration process of Letinous edodes was optimized by orthogonal test. Results showed that the three factors had impact on the drying time, reducing sugar content, amino acid content, lightness and the rehydration ratio of product. The infection order of each factor was the ultrasonic power>permeate concentration>ultrasonic treatment time for drying time. The optimum combination for drying was ultrasonic power 250 W, ultrasonic time 15 min, the permeate concentration of 15%, with letinous edodes drying time 7.4 h and rehydration ratio 4.55. These meaned that penetration combined with ultrasonic could improve the drying efficiency of Letinous edodes and quality of the product.