Using core，drilling，logging and seismic data，the development and sedimentary evolution of biolimestone at the lower Es1 in Changdi area of Zhanhua sag were researched. The Es1 in Changdi area is defined as a third-order sequence，and the biolimestone developed in the lower Es1 was divided into 3 fourth-order sequences. The lacustrine transgressive system tract and the lacustrine regressive system tract，where the biolimestone both developed，were also identified. The development of biolimestone is affected by paleo water depth and paleogeomorphology. There are 3 types of paleo water depth variation in the lower Es1，namely the water withdrawal，the high position water and the low position water. Through paleogeomorphology restoration，it is clear that the biolimestone in the lower Es1 is mainly distributed in the southeast and eastern slope trough. Based on the layers and its development characteristics，3 types of interior structure were categorized in the biolimestone，and then it is determined that there are two development modes in the study area，which are the biolimestone developed in gentle slope and the biolimestone developed in trough. Due to the periodic change of the lake level，the distribution of the biolimestone in the lower Es1 also changed correspondingly. The biolimestone is thicker around the uplift and thinner along the gentle slope direction，and its belt-like distribution is parallel to the periphery of the buried hill.