To study temporal characteristics of symmetry perception symmetric dot patterns were successively presented. Each pattern differed from others but all patterns in a stream were symmetric about identical axis. Task was to judge orientation of axis of symmetry (right or left diagonal). The total duration of the stream was fixed to 853ms, and presentation frequency was varied among 1.2 - 75Hz. Higher frequency meant larger number of patterns in the duration. Although such stimuli prevented the observers from scrutinizing each pattern, resulted performance was better compared to static presentation in same duration (experiment 1). Following experiments probed what enhanced symmetry perception of the successive stimuli. Experiment 2 contrasted (a) unique patterns condition in which all unique patterns were presented in a stream same as experiment 1, and (b) 4 patterns condition in which only 4 patterns were repeatedly presented in a stream. The latter yielded worse performance, suggesting that larger number of unique patterns, not flickering of patterns, improved the performance. In experiment 3 each trial presented 4 streams, and they all comprised of same set of 16 patterns (16 patterns condition) or they were repetitive presentation (same as experiment 2) of unique set of 4 patterns (4 patterns condition). 16 patterns appeared 4 times in one trial of both conditions, whereas one stream contained more patterns in 16 patterns condition. In result 4 patterns condition showed worse performance. This result suggested that larger number of patterns in limited temporal window improved the performance. Further experiment suggested that noise reduction underlay the improvement. In conclusion successive presentation of dot patterns in brief duration improved symmetry perception. Such improvement implies that temporal summation of visual information may occur in the mechanism of symmetry perception.