Abstract: In order to study the acoustic emission(AE) characteristics of dam concrete under bending tension in different loading rate, and to get further understanding about the dynamic damage process of dam concrete, unnotched wet-screened concrete beams were tested in MTS materials test system under bending tension in four different loading rates. The results showed that, with the increase of loading rate, the accumulated hit number decreased and the peak value of AE hit rate increased, the percentage of AE hits in low amplitude(35~40 dB) increased, and the average values of count, signal energy and duration of AE hits were increased, as well, Less AE events(microcracks) generated and the AE events tended to distribute in a smaller range, while in lower loading rate. Oppositely, AE events tended to distribute in a wider range.