The crosslinked polymers, poly(stearylmethacrylate-co-divinylbenzene) [CP(SMA-co-DVB)] and poly(t-butylstyrene-co-divinylbenzene) [CP(tBS-co-DVB)], and CP(SMA-co-DVB)/PtBS IPNs, were prepared by the polymerization of corresponding monomer pairs in the presence of BPO. The structures and thermal properties of CP(SMA-co-DVB), CP(tBS-co-DVB), and the IPN were determined by FT-IR, DSC, and TGA. The oil-absorptivities of CP(SMA-co-DVB) and CP(SMA-co-DVB)/PtBS IPN decreased with increasing concentrations of DVB and tBS: respectively. The highest oil-absorptivities of CP(SMA-co-DVB) and the IPN(PtBS : 25%) were 615 % and 330 %, respectively. The toluene absorptivity of the synthesized polymers decreased in following order : CP(tBS-co-DVB) > CP(SMA-co-DVB) > IPN(PtBS : 25 %), IPN(PtBS : 50 %) > IPN(PtBS : 75 %) at immersion above 60 min.