Purpose The purpose of this paper is to build a mathematical model of men’s wear prototype, so that the computer can draw men’s wear prototype automatically. Design/methodology/approach First, the bust line, front and back center line, waist line, side seam, front chest width and back width line in the coordinate system are expressed by equations. Then, a parabola is used to establish a neckline curve, a linear equation is used to establish a shoulder oblique line, and a double ellipse is superposed to construct the armhole arc. Finally, all the garment prototype curves are built mathematical models. Findings The result shows that every curve of garment prototype can be expressed approximately by mathematical model. Originality/value This research lays the foundation for the automation and intelligence of garment pattern-making.