Prior to considering the hybrid or combined seal packing with high efficiency, leakage flow characteristics of several kinds of seal packing, such as normal, guardian, brush and honeycomb, are investigated. Three-dimensional RANS based CFD analyses are performed efficiently with minimum circumference angle and periodicity boundary condition. The leakage mass flow rate is computed with different outlet static pressure in the operating condition with steam flow. Three-dimensional rotating seal tests are also performed to compare results of three-dimensional RANS solution in the different temperature and rotational speed with dry air conditions. Finally, It is found that leakage mass flow rates are commonly decreased with higher temperature and rotational speed in all kinds of seal packing.