1. A computer-readable translation memory adapted to sentence-based translation comprising: a first retrieval dictionary of a first language having a first dictionary TRIE structure and a first index TRIE structure; and a second retrieval dictionary of a second language having a second dictionary TRIE structure and a second index TRIE structure, the first and second dictionary TRIE structures respectively storing sub character strings on respective paths from roots to multiple nodes thereof, the first and second index TRIE structures respectively storing index information to specify the sub character strings stored in the first and second dictionary TRIE structures, wherein the index information stored in the first index TRIE structure of the first retrieval dictionary includes identification information that identifies the index information in the second index TRIE structure to specify the sub character strings in the second retrieval dictionary that are translations of sub character strings in the first retrieval dictionary, and wherein the identification information is a pointer to a memory location of index information in the second index TRIE structure that specifies the sub character string in the second retrieval dictionary that is the translation of the sub character string in the first retrieval dictionary.