A study has been made on the die-swell and rheological properties of bicemponent polymer blends of low density polyethylene(PE), polypropylene(PP) and polystyrene(PS); PE/PP, PE/PS, and PP/PS. In the case of PE/PP blends the continuous phase transferred from PE to PP at the PE content of 60wt%. Meanwhile the PE/PS and PP/PS blends the continuous phase transferred from PE to PS and from PP to PS at the PS content of 60wt%. respectively. The die-swelling ratio. normal stress difference(N1) and dynamic shear viscosity of PE/PP blends appear, to show same tendency by chaneine the blend-ratios. For the cases of both PE/PS and PP/PS blends, where PE and PP are in the continuous phase, the die-swelling ratios increase as the N1 increases but decrease as the dynamic shear viscosity increases. But N1 of the PS has been found not to contribute to the die-swelling ratios when PS is in the continuous phase.