Abstract: The aim of this study was to analyse the mutation possibility of influenza A (H5N1) virus of Banten Province strain. The H5N1 amino acid sequences of haemagglutinin (HA) and neuraminidase (NA) were analysed by multiple alignment method using BLAST tool, ClustalW and Bioedit 7.0.1. programs. The results of analysis were followed up by mutation analysis using Amino Track, secondary structure, post translation modification analysis, phylogenetic tree and homology modelling. From the analysis, five point mutations were revealed, namely change of haemagglutinin at position 185, 272 and 309 and neuraminidase at position 244 and 252. Conserved region prediction were determined to be at position 1-552 of HA and at position 1-39, 41-251 and 253-449 of NA. Secondary structure prediction showed a change in HA structure at position 309, namely coil into helix transformation and in NA structure at position 244, namely coil into extended strand transformation. Change of hydrophobicity happened only to HA at position 185 and 272. Mutation did not have any influence on post translation modification. Phylogenetic tree analysis and homology modelling also did not reveal the creation of a new strain.