Abstract: The experimental stimuli paradigm was:warning tone──priming character operating character.The task of the subjects was to associate a character which should match the operating character and form a word with it.Experiment was divided into two items according to the categories of the associations:concrete and Abstract:A control item was conducted. The operating characters were divided into known and unknown characters in every item. The EEG electrodes were fixed at Fz,Cz, Pz,midpoint of P3-T5 and midpoint of P4-T6.It was observed that:(1) Chinese word- meaning association evoked greater amplitudes of P3 and positive slow wave (PSW).(2) The unknown character association invoked stronger increase in peak latency and amplitude of the PSW than the known character association did.(3)The PSW amplitudes which induced by both known and unknown characters associations of control item were the largest in the three items.(4)A pure psychological component P800 was extracted from PSW,it was the companion of the features of unknown character alone.(5) The P800 onset latency of the control item was the longest in the three items.The results proposed that PSW not only reflected the completion of a processing in the brain,but also related to the multiple processing of the sound,form,meaning and the association of Chinese characters.These proposed that it was a composite wave,The sound, form and meaning of Chinese characters have an intricate relationship and it is difficult to cut them apart.The PSW and P800 could be used as an indicator to identify whether the Chinese characters are known or unknown by the subjects in the present experimental conditions.

Key words: Chinese character, known, ERP, PSW, Component P800