The gravity anomaly used in this study was obtained by merging EGM2008 gravity anomaly and observed gravity anomaly. The Moho depth beneath the eastern Dabie Orogen was obtained by frequency domain inversion of merged gravity anomaly. In combination with regional tectonic and seismic data,the Moho undulation and its tectonic implications were discussed. The results show that:① the depth of the Moho beneath the eastern Dabie Orogen reaches the maximum value of 42km,while the Moho depth of Yangtze block is intermediate,and the Moho of the North China block is the shallowest. This suggests that there exists a crustal root of the eastern Dabie Orogen and the Moho undulation reflects the tectonic features of different tectonic blocks. ② Steep Moho gradients along the north and south margins of the eastern Dabie Orogen locate at Qingshan-Xiaotian fault and north of the Xiangfan-Guangji fault respectively,represent the subductions of the North China block and the Yangtze block beneath the Dabie Orogen,and indicate the locations of deep suture zones. The Moho undulation shows that the Tanlu fault zone is the boundary of different tectonic blocks,and has extended to crust-mantle boundary or more deep. Within the eastern Dabie Orogen,the west side and east side of Shangcheng-Macheng fault were uplifted out of sync. ③ The great majority of earthquakes in this region occurred above the Moho interface. Steep Moho gradient zones,the Moho uplifting zones and transition zones of different Moho undulation areas provide deep structural environments for seismic activities.