DNA barcoding is a strong species identification tool for all animal taxa, and can easily be conducted when materials are under DNA friendly conditions. In contract, a full-length (659 bp) sequencing has been limited for the degraded DNAs extracted from old museum specimens. The initial challenges to retrieve the authentic DNA fragments from old museum specimens were attempted by obtaining short sequences (<300 bp) with the cloning process after PCR, making it both expensive and time-consuming. In this study, we employed a modified method to analyze the full-length DNA barcoding regions in 31~52 year-old butterfly specimens (301 dried specimens of 39 species) using direct sequencing after PCR with two different methods: 1) the successful PCR rates of 0 to 5.6% using four universal primer sets were too low to obtain authentic sequences and the cross-contamination was detected in almost all successful amplicons; 2) the success rates of PCR using specie-specific overlapping primer sets were distinctly high, reaching up to 75% with 98% authentic and 2% non-specific sequences. Thus, the result showed the method that using species-specific primer set per species yields the most effective success rates of both PCR and sequencing from degraded DNA without incorrect sequences.