The effects of weight-average molecular (

M

w

)

molecular weight distribution (MWD)

and isotacticity on the linear viscoelastic behavior of polybutene-1 melts are studied. It is observed that the linear viscoelastic region becomes slightly narrower with increasing frequency. In frequency sweeps

the transition of the polymer melts flow from Newtonian flow to power-law flow can be observed. The melts with higher

M

w

and/or broader MWD

as well as higher isotacticity exhibit higher complex viscosity

zero shear viscosity

viscoelasticity moduli

relaxation modulus

broader transition zone

while lower critical shear rate

non-Newtonian index

and the frequency at which elasticity begins to play an important role. The relationship of zero shear viscosity on

M

w

has been established

which agrees with the classical power law. Furthermore

it is found that the cross-over frequency decreases with increasing

M

w

and the cross-over modulus increases with narrowing MWD.