We choose petroleum ether and n-heptane as poor solvent and selective solvent to swell styrene-butadiene-styrene (SBS) and prepare a kind of swelling SBS sample with different swelling degrees. The steady rate sweep tests have been carried out and the steady zero shear viscosities have been obtained for two kinds of equilibrium swelling SBS. Furthermore, the dynamic frequency sweep tests have been performed for swelling SBS with different swelling degrees. The test results show that the curves of dynamic storage modulus (G’) is always located over those of dynamic loss modulus (G”), which exhibits that the viscoelastic behaviors of all the samples is charged by elasticity in the whole frequency range measured. The poor solvent give less destroy to the network structure of SBS than the selective solvent.