A method to translate Chinese text into Chinese sign language is introduced, and how to present gesture by a 3D virtual human, to help the deaf communicate with the hearing. In this method, an initiate database including all sign words motions is firstly created based on a motion capture method, where two data gloves and three 6-DOF position tractors are used to record the motion of a real person when he or she demonstrates each sign word. Then all motion data can be tuned accurately and easily by modifying the gestures just on some control points. After that, a database that contains of all sign words has been built up. Given a sentence of text, the motion of each word can be found in the database, concatenated one by one, and presented smoothly by a virtual presenter who is represented by a VRML virtual human model, then the sentence is translated into Chinese sign language. To help the deaf study, watch TV, and browse Internet, a system that can be used to translate Chinese text into Chinese sign language is developed in the PC/Windows/VC environment, and all most of generating signs by this system are very realistic and smooth as confirmed by a lot of teachers in deaf schools. The database of this system contains motions of all 5 596 Chinese sign words collected by a handbook of Chinese sign language.