A series of 4(3H)-quinazolinone derivatives containing a Schiff base moiety weresynthesized and their antiviral activity against tobacco mosaic virus (TMV) was evaluated using half-leaf method in vivo. Bioactivity results exhibited that the target compounds 3a-3x under 500 μg/m Ldisplayed moderate to good anti-TMV activities with the curative activity, protection activity, andinactivation activity values of 40.4%-53.1%, 51.2%-72.6%, and 46.0%-90.7%, respectively. Especially,compound 3d showed excellent protection activity against TMV, with a half-maximal effectiveconcentration (EC50) value of 203.89 μg/m L, which was even superior to that of ningnanmycin (214.90μg/m L). SAR analysis showed that compounds with electron-withdrawing groups at R1 and R2 positionsdisplayed better anti-TMV activity. These results indicated that the series of 4(3H)-quinazolinonederivatives containing a Schiff base moiety can effectively control TMV.