Abstract: Here in the article are briefly dealt 4 modes frequently used by scholars both at home and abroad to describe LY crude oil rheologic curve. Particular analysis is amde of mode (1)τ= τ0 + μ_pγ and (2)τ =τ0 + Kγⁿ with experiement data obtained, Mode(2) is regarded more accurate as oil tempsrature is close to the pour point. As for pipelines operating at underload, it is necessary to fix by raeasuse the equilibrium rheologic curve in the range of low shearing rate in order to obtain rheologic parameter.