Abstract: Taking fields of Bohaiwan Basin as an example and combining with several forming theory of dolomite, lacustrine dolomite reservoirs in Bohai oilfield was discussed in terms of lithology characteristics, logging trace, thin section analysis and origin of lacustrine dolomite.It's found that the distribution of dolomite is dominated by climate and palaeogeomorphology, and the distribution of dolomite was summarized based on lake level change, palaeogeomorphology, seismic data, depositional environment and lay flattening technique.