A series of diversified glucosamine derivatives(3a-3y)was synthesized and theirantifungal activitywas examined against four kinds of phytopathogens, Fusarium graminearum(F. graminearum), Fusarium moniliforme(F. moniliforme), Curvularia. lunata(C. lunata), and Rhizoctonia solani (R. solani)which cause seriously economic losses worldwide by affecting crops. The compound 3oshowedremarkable antifungal activity against F. graminearumwith EC50values of 3.96 μg/mL, compared to the standard drug triadimefon (10.1μg/mL).3D-QSAR model with the statistically recommended values (r2= 0.915, q2=0.872)show that positive charge group and bulky groupin the benzyl ring were favorable for the antifungal activity. Enzyme activityassays confirmed that 3ohasamoderate inhibition oftrehalasewith inhibition rate of 51.4%at 5 μg/mL, which is comparable to those of commercial inhibitors validamycin Awith inhibition rate of 83.3%.Molecular docking analysis revealed that 3oalso had a hydrogen bond interaction with key amino acid residue compared to validoxylamine.