Objective To study the method of decreasing dental anxiety（DA） on root canal treatment. Methods 360 patients were divided into group A, group B and group C. Parol and written notice about the content of root canal treatment were given to the patients of group A, written notice and psychological communication to group B, written notice, psychological communication and local anesthesia to group C. The change of DA level were measured in patients of three groups during treatment period. The patient′s fear degree were evaluated by means of visual analogue scale（VAS）. The data before and after root canal treatment were analyzed. Results The level of DA decreased along with the increasing of treatment frequency. The decreasing of group C was most obviously, next to group B. There were statistical difference before and after root canal preparation in the DA of same group（P
