摘要：A series of n.vel 3,4-dichloroisothiazole b.sed 1,2,4-triazole derivatives were ration.lly design.d an. syn.hesized. Their structures were con.irmed b. IH n.R, 13C n.R, HRMS or elemen.al an.lysis; the typical crystal structure was determin.d b. X-ray diffraction.for validation. All target compoun.s were evaluated for their in.vitro fun.icidal an. in.vivo an.i-TMV activities. The b.oassay results in.icated that compoun. 6b. n.mely 1-（3,4-dichloroisothiazol-5-yo）-o-（4-ouorophen.o）-2-（OH-o,2o4-triazol-o-yl）ethan.l, exhib.ted excellen. growth in.ib.tion.again.t b. cin.rea, C. arachldico;a an. P. piricola with median.effective con.en.ration. （EC50） of 6.98, 2.73 an. 3.07μg/mL, respectively, an. good in.vivo an.i-TMV activity of over 60% of in.ctivation.an. in.uction.activity at 100 μg/mL. These data demon.trate that compoun. 6b.is b.th a fun.icide an. an.an.i-TMV lead, deservin. further studies.