Abstract: This Paper is about the study of biological potential and bioelectrochemistry on tooth. For the first time a stable constant potential of tooth has been discovered by using electrochemical method. Statistical average with regard to measurement of 51 cases of teeth 1s 11.16 mV. This study confirmed H.C. Heimanson' s hypothesis in 1969── "electron current flows to dental pulp from tooth surface" and offered an objective an experimental foundation. The electrochemical experimental method for simulating the tooth potential was established.Applying the data of bioelectric field, feasipility of F^-and Sr²⁺transferred into the tooth the hard organism was studied quantitatively and qualitatively. F^-ion is useful for the prevention of tooth disease, but action of Sr²⁺still needs to be discussed further.

Key words: Biological potential, Ion transfer, Teeth