In order to find novel biologically active pesticide lead compounds, twenty-one novel 3-[(5-benzylthio-1,3,4-oxadiazol-2-yl)methyl]benzo[d]thiazol(oxazol)-2(3H)-ones were synthesized by 2-benzothiazolinone/benzoxazolone as starting materials via substitution, hydrazine, cyclization and the last benzylation reaction. The structures of the title compounds were characterized by 1 H NMR, IR, EI-MS and elemental analysis. The preliminary bioassay results indicated that most of them showed moderate inhibition activity against Colletotrichum orbiculare, Botrytis cinerea and Rhizoctonia solani at 50 mg/L, and the inhibition rate of compound 5b against Botrytis cinerea and Rhizoctonia solani reached above 85%.