A novel polymer was made from a blend between cassava starch (CS) and carboxylated styrene-butadiene rubber latex (CSBR) (CS/CSBR) blend in the presence of potassium persulfate (K2S2O8) using the aqueous solution-latex method. The effects of CS content, K2S2O8, reaction time, and temperature on the %gel content of the CS/CSBR blend were investigated. The highest gel content was found at 0.5/1 CS/CSBR blend and its value was 85% when using 1g K2S2O8 at 70 degrees C for 2h. The swelling ratio of the samples increased as function of CS portion in the CS/CSBR blend in water. The maximum swelling ratio of around 200% was found in the 1:0/1 CS/CSBR blend in water. The toluene resistance and hydrophilic behavior of the CSBR were improved by the addition of the CS. The blend exhibited excellent tensile strength properties relative to those of the corresponding CS/CSBR blend. According to scanning electron microscopy, tensile fractured surfaces of various CS/CSBR blend samples demonstrated better interfacial adhesion achieved by the modification. Finally, the biodegradation of the CS/CSBR blend in soil was also investigated. This sample was applied to use in decoration materials such as packaging and artificial flowers.