Since thermoplastic starch can not be used directly due to its poor properties in processing, thermoplastic starch /ethyl cellulose composite is prepared by blending method in this work. The effect of the composition and the structure on the properties of the composite is studied. The results indicate that glycerin is a better plasticizer in the processing of the thermoplastic starch compared to glycol. The mechanical properties of the thermoplastic starch are improved obviously after blending with ethyl cellulose. The composite exhibits comprehensive properties as the content of the ethyl cellulose is kept at 10%, which also has a reasonable cost.