A translation system including: a bilingual data storage section, a plurality of pieces of first language simple sentence data and a plurality of pieces of second language simple sentence data being stored in the bilingual data storage section while being associated with each other so that the first language simple sentences and the second language simple sentences respectively make pairs; and a target language simple sentence data output section which outputs target language simple sentence data corresponding to a target language simple sentence which is a translation of a given source language simple sentence based on source language simple sentence data corresponding to the source language simple sentence. The target language simple sentence data output section receives first-language-source-language simple sentence data, selects first language simple sentence data from the plurality of pieces of the first language simple sentence data stored in the bilingual data storage section based on the received first-language-source-language simple sentence data, and outputs the second language simple sentence data associated with the selected first language simple sentence data as the target language simple sentence data.