We describe a new strategy for LC-MS/MS based full length protein sequencing. Protein samples were unspecific hydrolyzed by three different methods(proteinase K, papain and microwave-assisted acid hydrolysis) to improve overlapping degree of peptides. After LC-MS/MS analysis, peptide sequences were gernated by de novo peptide sequencing program Pnovo. A new sequence assembly program, based on de brujin graph and Overlap-Layout-Consensus strategy, was desined to generate full length protein sequence using Pnovo results.