A series of novel N-tert-butyl-N′-acyl-5-methyl-1, 2, 3-thiadiazole-4-carbohydrazides were designed and synthesized. Their structures were characterized by melting points, 1H NMR, IR, ESI-MS, and elemental analysis. The bioassay tests indicated that compound 7o exhibited excellent direct anti-TMV activity and induction activity in vivo at 50μg/mL, which was better than that of Ninamycin and tiadinial. Our studies indicated that 1, 2, 3- ...