摘要：A series of novel 3,4-dichloroisothiazole based 1,2,4-triazole derivatives were rationally designed and synthesized. Their structures were confirmed by IH NMR, 13C NMR, HRMS or elemental analysis; the typical crystal structure was determined by X-ray diffraction for validation. All target compounds were evaluated for their in vitro fungicidal and in vivo anti-TMV activities. The bioassay results indicated that compound 6b, namely 1-（3,4-dichloroisothiazol-5-yo）-o-（4-ouorophenyo）-2-（OH-o,2o4-triazol-o-yl）ethanol, exhibited excellent growth inhibition against B. cinerea, C. arachldico;a and p. piricola with median effective concentrations （EC50） of 6.98, 2.73 and 3.07μg/mL, respectively, and good in vivo anti-TMV activity of over 60% of inactivation and induction activity at 100 μg/mL. These data demonstrate that compound 6b is both a fungicide and an anti-TMV lead, deserving further studies.