The kinds of change in facial expression which can be produced by a sender's neural control of facial muscles, and, at the same time, can be visually perceived by a listener are described in discrete symbols. The linguistic information supplemented by the facial expressions in signing is categorized into syllabic, lexical and syntactic components. In order to control the facial expressions for this linguistic information, the timing and duration of the symbols are specified, and, by applying a set of concatenation rules, the control commands are generated. The adequacy of the symbolic descriptive system and its control rules have been examined through a computer synthesis of artificial facial expression, taking the example of transmitting syntactic information in traditional Japanese sign language. These facial expressions are combined with the symbolic descriptive system for hand shapes and arm actions and their control rules for the pictorial display of signing gestures.