Magnetostratigraphic study at the CQJ4 borehole in Dagang area of Tianjin indicates that the Quaternary/Tertiary boundary (2.58 Ma) locates at depth of 340 m, and the base of the Middle Pleistocene series, corresponding to B/M boundary is located at 74 m. Microfossil analysis reveals three transgression layers in the CQJ4 borehole, which are at 4.2~12.0 m, 16.4~30.2 m, and 56.55~58.00 m, respectively. Comparing with data of the drilled boreholes in the Bohai coast, the three transgression layers should belong to “Transgression Layer Ⅰ, Ⅱ, Ⅲ” from new to old in time. Four geomagnetic excursion events in Brunhes normal chron are recorded in the CQJ4 core sediments, which could be correlated to Blake (120~110 ka), Jamaica (215~205 ka), Calabrian Ridge 1 (325~315 ka), and Calabrian Ridge 2 (525~515 ka), respectively. Based on the age of geomagnetic excursion events and the correlation of magnetic parameters of CQJ4 borehole and ODP 677 oxygen isotope proxy, the three transgression layers are correlated to “Transgression Layer Ⅲ, Ⅳ, Ⅴ” in Chinese coastal plains, respectively. This correlation is conflicted with the general consideration of three transgression ages in the Chinese coastal plains which is clearly difficult to solve the problem of very low sedimentation rate between the base of Late Pleistocene (depth at 58m) and the B/M boundary (depth at 74m).