Abstract: The earthquake damages of engineering structures have been affected by the amplitude, frequency and duration of the strong motion records. However, there are relatively few published duration equations available in Chinese mainland. In this paper, we collected the strong motion records with magnitude M_W5.0—6.6 during 2007—2015 from Chinese digital strong motion networks. Considering the effects of source, path and site, the random-effected regression technique was adopted to fit a predictive equation in respect to the significant duration. In comparing the predicted durations with other studies, it is shown that this predicted significant duration increases with the increased earthquake magnitude or the increased distance, and decreases with the increased v_S30. Furthermore, it has the similar characteristics with other studied regions.