A trim distance as a phylogeny-based distance between two positions in nucleotide sequences is formulated as an LCA-preserving distance between the trimmed phylogenetic trees by the positions. In this paper, in order to investigate the positions as packaging signals of nucleotide sequences in influenza A (H3N2) viruses, we compute and compare the trim distances between positions in the nucleotide sequences of influenza A (H3N2) viruses provided from NCBI.