The Yonganzhen delta is developed in Minfeng sag and its peripheral area are important oil and gas accumulation belts in Dongying depression, Bohaiwan Basin, China. Based on the principles of seismic sequence, combined with logging and drilling, the target strata of Yonganzhen delta, the middle and the lower submember of third member of Shahejie formation (Es3z-Es3x) are divided into a third-order sequence separately. In the sedimentary stage of Es3z, three fourth-order sequences (MSC1-MSC3) and eight fifth-order sequences (Z1-Z8) are developed; in the sedimentary stage of Es3x, two fourth-order sequences (MSC4-MSC5) and two fifth-order sequences (X1-X2) are developed. Meanwhile, the scales of Yonganzhen deltaic deposition was small in the periods of MSC5-MSC3; in the period of MSC2, the strength of source supply increased from the Qingtuozi salient, the Yonganzhen delta prograded massively, and reached the downthrown block of Shengtuo fault with the depositions of mixed sources; in the period of MSC1, the Yonganzhen delta migrated to the north is affected by the deposition of the Dongying delta. Moreover, the Yonganzhen delta has the characteristic of selfsimilarities for development of sandbody controlled by sequence. The self-similarities illustrate that the delta sandbody is developed within the dropping semi-cycle in each grade of base level cycle, with the sand content higher than that of the rising semi-cycle.