Double thiadiazole were synthesized by 5-amino-1,3,4-thiadiazoles, which was synthesized from thiosemicarbazide with 1,3-Dibromopropane. And a series of double thiadiazole-basedα-Aminophosphonates were accepted by a reaction of different aldehydes and phosphates. The structures of these compounds were confirmed by UV, IR, 1HNMR , 31PNMR and elementary analysis. Preliminary bioassay showed that they all have excellent fungicidal activities against Botrytis cinerea, Gibberella zeae, Physalospora pinicola and Rhizoctonia solani .