Five series of new heterocyclic compounds of 1,2,4‐triazole Mannich bases, 1,3,4‐oxadiazole Mannich bases, 1,3,4‐oxadiazolines, 1,2,4‐triazolo[3,4‐b]1,3,4‐thiadiazines and 1,2,4‐triazolo[3,4‐b]1,3,4‐thiadiazoles, in which 1,2,3‐triazolyl and isoxazolyl have been united, were synthesized from the intermediate of 5‐methyl‐3‐(2‐phenyl‐2H‐1,2,3‐triazol‐4‐yl)isoxazole‐4‐carbohydrazide, Their structures were established by spectroscopy.