Petroleum pitch was modified by waste styrene-butadiene-styrene copolymer (SBS) and the cokes were obtained via the co-carbonization method. The waste SBS content and the co-carbonization temperature have important effects on the morphology and structure of resultant cokes. It can be found that adding waste SBS can obviously increase the methylene content in the cokes and improve the thermal stability of the co-carbonized products. The coke of MP7.5-450-10 exhibits almost 100 vol% anisotropy region with streamline texture and has the lowest weight loss of 5wt%. The coke of MP10-450-10-C has the smallest carbon interlayer space and the largest crystallite thickness. Co-carbonized products at 900°C have the porous structure similar with carbon foam, and the large pore diameter is in the range of 200–1000μm. Importantly, there are some mesopores existing in the products. Moreover, adding waste SBS can increase the specific surface area and the pore volume of carbonized products. The samples of MP7.5-450-10-C has some mesopores with the diameter of 3–50nm, and the pore volume is 0.013cm3g−1.