Die-life prediction system with fuzzy language is developed for computer-aided forging process planning. The authors research into forge expertise for the prediction. Then, we think them as evaluation of the risk to make die-life shorter than the standard parts whose life is obvious. Plural standard parts makes the life of unknown one clear with comparing these risks each other. The life of the part is between the ones of high risk processes and the ones of low risk processes. The authors implement this idea on computer with fuzzy language computations. Risk is described by structured fuzzy language but numerous expression, such as 'high' or 'very low'. The system computes it with this structure, and approximate to language expression after then. It also predicts die-life by fuzzy reasoning from the risk to life and makes language approximation on life such as '50 000 to 60 000'.