Abstract: Rheological parameters and density identification of drilling fluids is a very important work, it determines the the success drilling.Through experiments on the correlation of drilling fluids density and relevant parameters, reffering to the sea surface drilling fluids formula, drilling fluids with different density was prepared, their performance was measured, the experimental data was mapped, and mathematical models of density and rheology parameters was established.According to mathematical models, rheological parameters of drilling fluids can be determined by drilling fluid density initially.