To analyze the function and mechanism of plant U-box protein in plant innate immunity, the U-boxstructure characteristic and the difference between U-box and RING-finger domain were introduced in thisreview. Moreover, the classification of U-box protein and classification characteristics were summarized. Inaddition, the functions and mechanism of U- box protein, such as SPL11, PUB12/PUB13 and PUB17, inregulating plant PTI signaling transduction were reviewed in this paper. Similarly, the functions andmechanism of U-box protein, such as ACRE276, PUB17, CMPG1 and MAC3A/MAC3 B, in regulating plan...