A piezoelectric DNA sensor based on self-assembled monolayer technology was developed.In the experiment, 3,3′-dithiopropionic acid was applied to immobilize DNA, 1-ethyl-3-［3-(dimethylamino)propyl］ carbodiimide (EDC) and N-hydroxysuccinimide (NHS) can coat avidin on gold electrode, and then avidin can combine to different segment (25-mer biotinylated oligonuleotide and 169 bp biotinylated DNA probe by PCR) nucleotide on gold electrode surface. The consistency and speciality of the piezoelectric DNA sensor adopted above immobilization method was well. The sensor can be reused by electrode regeneration.