Based on detailedsedimentological and magnetostratigraphic study of Bg10 borehole(600m)in the northern coast of Bohai bay,there are 39 sedimentary units and 8 normal magnetozones and 7 reverse magnetozones according on 516 specimens (456 specimens subjected to progressive thermal demagnetization and 60 specimens subjected to alternating field demagnetization)calculated the characteristic remanent magnetization(ChRM)directions.Thinking about sedimentation rates of different magnetozones,Comparing to the geomagnetic polarity timescale(Cande et al.,1995;Gradstein et al., 2004),the normal magnetozones N1,N2,N3,N4,N5,N6 and N7 can be correlated with C1n,C1r.1n, C2n,C2r.1n,C2An.1n,C2An.2nand C2An.3n,the reverse magnetozones R1,R2,R3,R4,R5and R6 can be collated with C1r.1r,C1r.2r+C1r.3r,C2r.1r,C2r.2r,C2An.1rand C2An.2r.The B-M and MG boundary of borehole are located in 162.3 m and 475.8 mrespectively,and the age of the bottom is less than 3.596Ma.There have been three sedimentation phases.TheⅠphase which age was 3.3~3.5Ma and sedimentation rate was more than 130 m/Ma was tectonic active period and could be correlated with the phase A of Qingzang movement.TheⅡ phase which age was 1.9~3.3Ma and sedimentation rate was 112 m/Ma was tectonic silent period,and the sedimentary process could be controlled by climate change, but there had the different subsidence rate between Huanghua depression and Cangxian uplift.There was a tectonic active period aged 1.0~1.2Ma in the Ⅲ phase which age was 0~1.9Ma and sedimentation rate was 202 m/Ma,which could be correlated with Kunhuang movement.The sedimentary process should be controlled by tectonics and climate and the subsidence rates of Huanghua depression and Cangxian uplift have been different since 1.0Ma.Tangshan-Xingtai fault could be formed at 1.9Ma,and has developed one sag at the intersection with Zhangjiakou-Penglai fault.