Abstract: A process and a system for generating a knowledge code based on a text described in a natural language and converting the generated knowledge code into the text. The process includes the steps of preparing a text described in a natural language by means of a text describing assistant system, converting the text into an intermediate knowledge code, converting the intermediate knowledge code into the knowledge code, and inputting the knowledge code into a knowledge-based system. The text describing assistant system describes the text using a text generation tool by inputting describing items in accordance with a previously provided text description procedure. The conversion of the knowledge code into the text is performed by converting the outputted knowledge code into the intermediate knowledge code using an intermediate knowledge code converting unit, and converting the intermediate knowledge code into the text using a document description generating unit.