1�� Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology��Ministry of Land and Resources�� Qingdao 266071��Shandong��China; 2�� Qingdao Institute of Marine Geology��Qingdao 266071��Shandong��China; 3�� School of Ocean Sciences��China University of Geosciences��Beijing 100083��China

Detailed lithologic description��grain-size testing and foraminifer identification from the ZK1 of the five drilling cores in Yellow River delta have been done��with the analysis of their vertical distribution sequence�� The change of grain-size and standard deviation showed the sensitive grain-size population to sedimentary environment variation in ZK1 drilling core are 3. 75 �� 4 �� and �� 10 ���� The sedimentary environment of ZK1 in Yellow River delta can be divided into 4 stages through the analysis of sensitive grain-size population contents varied in depth��vertical distribution characteristics of grain-size parameters and foraminifer informations�� The first stage ( 0 �� 5. 14 m) is upper delta plain deposition from 1904 to 1976; the second stage ( 5. 14 �� 17. 41 m) is lower delta plain deposition since 1855; the third stage ( 17. 41 �� 22. 6 m) is continental shelf deposition before 1855; and thefourth stage ( 22. 6 �� 24. 6 m) is tidal flat deposition��