Objective To investigate the expression of Na +/Ca2 + exchanger 1(NCX1) channel protein in human odontoblasts(OD) and nervous tissue of dental pulp.Methods Twenty intact and healthy third molars extracted for orthodontic purpose were collected.The OD layer and nervous tissue were determined by dentin sialophosphoproteins(DSPP) antibody staining and modified Bielschowsky silver staining respectivelly.The immunohistochemical method was used to detect the expressions of NCX1 protein in human dental pulp tissue.The difference of expression of NCX 1 in human OD at different part of dental pulp was statistically analyzed using Image Pro Plus and SPSS software.Results NCX1 channel protein was mainly expressed on the cell body of OD,and nervous tissue of dental pulp.The expression level of NCX1 on the OD of crown pulp was higher(A=0.146±0.021) than that on the upper part of root pulp (A=0.120±0.034),but the expression difference was not significant(P＞0.05).Conclusions NCX1 channel protein was expressed on human OD and nervous tissue in dental pulp.