The terminal point information of area growth rate is usually used to characterize liquid phase fluidity of iron ore powder during sintering. However, this characterization doesn’t take process information into account. In order to avoid using several indexes to evaluate fluidity of iron ore powder, the factors that affect liquidity are analyzed, characteristic number (LD)which could quantitatively measure liquidity is deduced by dimensional analysis and Buckingham’s theorem. Equivalent characteristic number (Ld Θ)is concluded by simplified the characteristic number equation. The high temperature furnace is used to record the whole process information in experiment. The value of each kind of ores’ Ld Θ are calculated after starting point and ending point of liquid flowing are determined by basic experiment and control experiment. The data of liquidity of 5 kinds of mineral powder are measured under original standard and new standard, the result is respectively A>C≈D>B>E and Ld ΘA>Ld ΘD>Ld ΘC≈Ld ΘE>Ld ΘB. As a result, the two standards have identical results, but the new standard that combined important factors could distinguish the influence degree of each factors on fluidity.