A data sorting program that is capable of performing a data sorting process by using a small capacity of memory at a fast speed. A computer executing the data sorting program has the following functions. A concise ordered TRIE creator creates a root, sequentially reads the characters of each data, and when a prescribed number of data passed a certain node connected to the root before and a child node corresponding to a character next to a character associated with the certain node has not been created, creates the child node so that the child nodes of the certain node have a prescribed arrangement. A partition determination unit sets partitions between prescribed nodes. A data grouping unit groups the data into a plurality of data groups according to the partitions.