Abstract : In many ways, composite materials have been widely used in everyday life. However, most of the composite materials that have been successfully developed still use synthetic materials that are not environmentally friendly. In this study, it was intended to obtain environmentally friendly composite materials (GC) by utilizing unmodified and unmodified teak starch and arrowroot starch adhesives. Arrowroot starch modification was carried out using a solution of 1%, 3% and 5% Sodium Tripolyphosphate (STPP). GC material synthesis was done by mixing modified arrowroot starch and teak powder in a 50/50 (% weight) ratio and using hot press machines at 80oC, 3.0 MPa pressure for 10 minutes. An FTIR analysis clearly showed that the intensity of the phosphate (P=O) group in the wavenumber region of 1338 cm-1 for GC materials with modified teak sawdust. Based on the characterization results, it can be concluded that the modified arrowroot starch increased the values of density, strength and bending modulus and reduced the values of moisture content and thickness expansion. The highest increase in density, strength and bending modulus was experienced by GC material with arrowroot starch resin modified with STPP at a concentration of 3%, namely 7.3%, 11.9% and 30.06% respectively. The GC material also experiences the highest moisture content and thickness swelling decrease with arrowroot starch modified with STPP at a concentration of 3%, namely 21.9% and 8.0%, respectively. Although the use of modified arrowroot starch can improve the characteristics of the resulting GC material, the synthetic GC material does not fully meet the standards required by INS 03-2105-2006. Only the synthesized GC material's density value and moisture content can meet the INS 03-2105-2006 standard.