A successful synthesis of composite particles of hibiscus tiliaceus bark fiber (HBF) and carbon powder from coconut shell (CP) by hot press technique has been reported. The microstructure of samples is investigated using an SEM analysis to check the morphology of the composite. Ultimate tensile and flexural strength of CP/HBF/polyester composites are examined. The percentages of CP were defined as 15, 20, and 30 (% by volume) and the HBF percentages were 5 and 10 (% by volume). The results showed that the tensile strength, modulus of elasticity, and bending strength of the composites increased significantly close to 110% with the increase in the amount of CP in 5% HBF/polyester composites. Conversely, the mechanical properties are low when the powder content of hibiscus skin is 10% due to the presence of pores at the interface between the CP-HBF-polyester, the weak adhesion of the interface, and the HBF pulling out. The results imply that these composites can be an alternative building construction material.