To　compare　the　characteristics　of　Metal　Magnetic　Memory　Technique　(MMMT),　a　nondestructive　testing　method　applied　to　two　different　materials　(ferromagnetic　and　paramagnetic　materials),　AISI304　and　Q235B　vessels　has　been　developed　by　MMMT　respectively.　The　results　show　that　the　weak-magnetic　AISI304　material　becomes　magnetic　obviously　after　welding,　indicating　that　the　new　MMMT　method　is　feasible　in　testing　weak-magnetic　materials.　It　is　also　demonstrated　that　the　disorderly　magnetic　signals　of　pre-heat　treatment　welds　of　Q235B　become　uniform　after　heat　treatment.　At　the　same　time,　heat　treatment　does　not　alter　the　basic　characteristic　of　abrupt　change　and　overturn　of　magnetic　signals　at　the　welds　of　Q235B　vessel.