PURPOSE: A natural ingredient sheet composition is provided to improve tensile strength, flexural strength, flexural elasticity, heat resistance, fracture strength, and combustibility and to reduce costs and foul odor. CONSTITUTION: A natural ingredient sheet composition comprises 25-70 weight% of rice hull crushed material with a particle diameter of 50-300 micron; 20-60 weight% of a thermoplastic resin with a thermal deformation temperature of 90°C or more; 1.5-7 weight% of an anhydride maleic modified polypropylene with a compatibilizer; 1-6 weight% of an alkalizing agent; 0.05-1 weight% of a thermal stabilizer with a calcium-based nontoxic or inorganic metal; 0.05-0.5 weight% of a phenol mixed with an oxidation-preventing phenol and phosphorous; and 0.1-0.5 weight% of a paint consisting of carbon black or an inorganic compound. [Reference numerals] (AA) S1 step; (BB) Step of increasing interface binding force by generating rice hull pulverized product and converting the rice hull pulverized product into