A Bézier curve is a parametric curve frequently used, among others, in CAD programs, computer graphics programs (Corel Draw, Photoshop, GIMP, Adope Illustrator etc.) or vector graphics. The Authors of this study have presented the possibilities of application of Bézier curves as well as closed curves to measurements of length of handwriting line, writing density and to the parametric determination of similarity of shape of letters and signatures.