Silicone rubber is widely used in various fields but has low strength, whereas kenaf has higher strength. Therefore, this study aims to synthesise a new material that consists of both kenaf and silicone with three different variances and determine its properties using the three most common hyperelastic constitutive models: Neo-Hookean, Mooney-Rivlin and Ogden. In order to obtain the material constant of kenaf silicone biocomposite, experimental and numerical approaches are adapted. The xperimental approach involves synthesising of kenaf silicone biocomposite and uniaxial tensile test, while the numerical approach involves curve fitting method using an excel programme. Curve fitting method was used because the raw data from tensile test alone could not determine the material constant of agar silicone biocomposite. The results show that the numerical value of the material constant increases as the percentage of the reinforcement material (kenaf) increases. However, the tensile strength of the material decreases as the reinforcement material increases.