The sequence identity of two protein sequences of two species either in the same class or in the different classes finds the optimal relationship between the species.The identity is found by sequence alignment of two protein sequences that is executed from dynamic programming.Alignment algorithm based dynamic programming is applied for finding the similarity between the protein sequences.The pairwise global alignment has been done between two protein sequences of two species using Needleman-Wunsch algorithm to find how much homologous these species are.From this alignment, the research shows that how much these species exhibit the same genetic functions.