Paeonol contents in root barks, cores, stems and leaves of Paeonia suffruticosa Andr. from Nanling county, Anhui province were determined and paeonol was extracted with alcohol, acid alcohol and alkali alcohol. Sodium paeonol sulfonate was synthesized by treating paeonol with concentrated sulfuric acid and oleums, and its physicochemical properties were surveyed by HPLC, TLC, FTIR and UV. Antibiotic experiment on plant pathogenic fungi and bacteria showed that paeonol and sodium paeonol sulfonate had remarkably inhibitive effects on Xanthmonas oryzae pv. oryzicola, Pseudomonas solanacearum, Phyllosticta mali and Rhizoctonia solani. Paeonol and sodium paeonol sulfonate had antibiotic effect on maize sheath blight.