This study examines the preparation and characterization of Kenaf/Starch bio-composites used as filler and a matrix. Kenaf was cultivated in Chung-ju in Korea, and the Kenaf/Starch bio-composites were prepared under various conditions of kenaf fiber length (1-5 centimeters); the content of Kenaf fiber was 10%, 20%, 30%, and 40%, and the number of composite layers (one-four). Depending on the formation conditions of Kenaf/Starch composites, the physical properties such as tensile strength, elongation, and the young modulus of the Kenaf/Starch composites were measured. In addition, we measured the SEM cross-section images in order to investigate the interfacial adhesion properties of fractured surfaces. As a result, the tensile strength and elongation of the Kenaf/Starch composites were highest in the molding conditions of a hot press at $120^{circ}C$, 3000PSI of pressure, and for 30 minute periods. The result of measuring the physical properties of the composites manufactured by varying the content of Kenaf fiber when the content of Kenaf fiber was 30% as well the physical properties of the Kenaf/Starch composite was found desirable. It was found that the physical properties improved with more overlapped layers in the composites manufactured by varying the number of overlapped layers. Through the measuring of the SEM cross-section images, we found that the interfacial adhesion state between the filler and matrix of Kenaf/Starch composite greatly affects the physical properties.