The mechanical and water vapor permeability of starch/carrageenan cast films were investigated, the rheological properties of starch/carrageenan blends were also studied. The blends were prepared by different concentrations of starch and carrageenan. Three concentration of starch (0.75%, 1% and 1.25%) and two concentrations of carrageenan (0.5% and 0.75%) were used with adding 0.5% glycerol as plasticizer the results show that all samples behaves as non-Newtonian pseudoplastic fluid and obeys the power law relationship. The mechanical and water vapor permeability of the cast films increase with increasing carrageenan content