<![CDATA[The objective of the research were to analyze the characteristics and get the formula of rubber compound that was added with extract of Caesalpinia sappan wood and fillers of silica quartz sand and CaCO3 from shell. Factorial completely randomized design (RALF) with two factors was used. The first factor was the concentration of extract of caesalpinia sappan wood (ά) which was 3 phr, 6 phr, 9 phr, 12 phr and the second factor was the concentration ratio of silica from quartz sand and CaCO3 from shell (β) which was 10:90 phr, 25:75 phr, 50:50 phr, 90:10 phr. Parameters tested were tensile strength, elongation at break, after aging tensile strength, after aging elongation at break and color change. The results showed that treatment of extract of Caesalpinia sappan wood concentration, a mixture of quartz sand with shells and their interaction significantly affected to the tensile strength, elongation at break, after aging tensile strength and after aging elongation at break of rubber compound resulted. The best treatments met the requirements of rubber compound in accordance with for SNI were ά3β4 treatment (9 phr of extract of caesalpinia sappan wood concentration and 75:25 phr mixture of quartz sand with shell) with rubber compound characteristics for these parameters, tensile strength of 30 N/mm2, elongation at break of 496%, after aging tensile strength of 27 N/mm2 and after aging elongation at break of 457% and the total change of color difference of 19.9.Keywords: extract of caesalpinia sappan wood, quartz sand, rubber compound, silica, shell]]>
