Background & Aim: Personal identification of unknown cadaver has a great importance in forensic medicine. At present, DNA Typing is one of the main procedures in personal identification by extracted DNA of different tissue such as blood, Muscles, Liver or Spleen. In bodies who are putried or buried for a long time, decomposition and Environment factors cause to destruction of soft tissue. So DNA is degraded by endonuclease enzymes and polymerase chain reaction is inhibited by decay products. In such cases tooth and bones are suitable sources for DNA in forensic investigations. Additionally, in the severe bruns and air accidents, tooth has an important rule in identification.Materials & Methods: In this study, DNA was extracted from five unknown cadavers by using guanidinium thiocyanate-silica (GUSCN) method some modification is carried out in standard (GUSCN) for achieving better results and reducing artifacts. For evaluation of the procedure, extracted DNA was amplified and subjected to PCR for six short tandem repeats (STRs) loci named VWA, F13, CD4, THOl, FES/FPS and TPOX.Results: This study showed that quality and quantity of extracted DNA from tooth by method mentioned above is comparable with extracted DNA from blood and the alleles of tooth and blood belonging to same individual weve compared with standard allelic ladder for each locus.Conclusions: we suggest using of this method for DNA extraction of tooth as a valuable source in forensic personal identification.