In order to investigate the performance of castor oil-based bioasphalt blended asphalt mixture，design of AC-20C blended asphalt mixture with 5 different percentages of bioasphalt was conducted. Performance tests were then carried out on the specimens with optimum asphalt contents of respective percentages of bioasphalt. Based on the test results，the properties such as high temperature stability，moisture damage resistance，low temperature cracking resistance，and pavement structure design parameters were analyzed. The analyses indicate that with increasing percentage of bioasphalt，the high temperature stability，moisture damage resistance and compressive resilient modulus of the blended asphalt mixture decrease，but they satisfy the requirements of JTG F40-2004 within a certain range of percentage. The moisture damage resistance is significantly improved by adding hydrated lime. With increasing percentage of bioasphalt，the indirect tensile strength of the blended asphalt mixture decreases to the minimum value and then increases slightly，while the low temperature cracking resistance of the blended asphalt mixture increases. Hence，the use of castor oil-based bioasphalt as partial replacement to petroleum based asphalt in asphalt mixture is feasible.