This paper examines the results of earlier studies of radicals in the Tangut script and concludes that they have failed to grasp the special characteristics of this particular writing system.  The meanings which have been ascribed to radicals are shown to be only parts of the multiple meanings of radicals and are not always their primary meanings.

It is demonstrated that a graphic element, when serving as a radical, generally carries various, apparently unrelated meanings and the same graphic element, when serving as a phonetic, always represents various, apparently unrelated sounds.  A model of generative processes of Tangut characters is constructed with the view of explaining this phenomenon. According to this model, basic characters are created at first and all the other characters are derived from them by means of transformation.

This paper describes the characteristics of the Tangut script in terms of generative processes and compares the Tangut script with Chinese characters and Vietnamese characters (chu' nom).  The differences and similarities in their structures are briefly discussed from the viewpoint of their formation history.  As a concluding remark, this paper emphasizes the significance of the generative model in the comparative study of different writing systems, and in the search for the common principles among them.