Abstract: 【Objective】 To study the value-added effect of dibutylphthalate（DBP） on the pathogenic Fusarium in lily rhizosphere soil and its effect on the ultrastructure of the fungal cells,and to clarify the effect of DBP on the allelopathy of Fusarium.【Method】 In the experimental setup of 7 DBP concentration treatments,four Fusarium species（F. oxysporum,F. solani,F. tricinctum,and F. avenaceum） were cultured on the medium supplemented with DBP,and the growth and spore production as well as the submicroscopic structure of F. oysporum cells were measured.【Result】 DBP had a significant allelopathy inhibitory effect on Fusarium strains. Within the DBP concentration range of 0. 05 mmol/L to 4. 00 mmol/L,the colony growth rate decreased with increasing concentration,while the spore production decreased,resulting in an increase in synthetic index. The submicroscopic observation results showed that under the DBP treatment on F. oxysporum,both the fungal hyphae and spores were constricted and malformed,and these changes seem to be more serious with the increase of DBP concentration. In addition,plasmolysis was observed in some cells,and the cell wall and plasma membrane were disturbed,and some kind of black particles appeared in the cells.【Conclusion】 These results suggest that DBP has allelopathic inhibitory effect on the growth and development of Fusarium,the pathogenic fungi of Lanzhou lily wilt,and its pathogenicity,so it can be tried to apply it to the prevention and control of lily pathogenic continuous cropping disorder and soil-borne diseases.