Abstract: The artice has classified the viscous oil transported in ring into three fluid states: the liquid ring and core oil are laminar flow; the liquid ring is surge flow and the core oil laminar flow; both the liquid ring and core oil are surge flow. The floid state criterion are derived for indentifying the three cases mentioned above, the application of which is independant of the thickness of the liquid ring. Thus obtained are the formulas to calculate the speed distrbution and flow rate at the three states, with an applicable range of 0.5≤K < 1, of which K is the ratio of radius. The quantative expression for the eccentricity of the eccentric liquid ring is derived through force balance, pointing out that the effective way to reduce the eccentricity is to increase the viscous elasticity and speed of the low viscous liquid and bring down the thickness of the liquid ring. It is suggested that the concept "output efficiency" be used to confirm which one is better, the liquid ring or the conservative pipelining. The optimum radio of oil 10 water is found. It is proved theoretcally as well that the efficiency of the liquid ring pipelining is very high, and particularly suitable for carrying high viscous oil which is otherwise difficult to delive.