Objective To observe the effect of single and repeated predatory sound stresses on the anxiety-like behavior of Sprague-Dawley rats. Methods After single and repeated predatory sound stresses, the behaviors of rats were recorded by open-field test (OFT) and elevated plus-maze (EMP) test, respectively. The mean velocities of OFT and EPM were measured as an index of movement, and the percentages of distance traveled (D%) and persistent time spent (T%) in the center zone of OFT and open arms of the EMP, respectively, were determined as parameters of anxiety-like behavior and used to evaluate the anxiety of rats. Results Before a single stress, movement in each group of rats was similar, but showed a lower baseline during anxiety. At days 1 (OFT), 3 (OFT) and 7 (EPM) after stress, 10 and 60 min treatments with a single predatory sound stress significantly decreased the D% and T% in the center zone of OFT or open arms of the EPM compared with control and white noise groups, respectively ( P < 0. 01). Similarly, rats at days 1 (EPM), 3 (OFT) and 7 (EPM) after repeated predatory sound stresses exhibited lower D% and T% in the center zone of OFT or open arms of the EPM compared with control and white noise groups, respectively ( P < 0. 01). At day 7 after repeated stresses, diazepam (1 mg/ kg i. p.) reversed the levels of anxiety in predatory-sound-stressed rats ( P < 0. 01). Conclusions Predatory sound stress increases the anxiety-like behavior of rats. In addition, a single predatory sound stress over a short duration (10 min) induced stress that persisted for at least 7 days, with no tolerance to repeated stresses.