The effectiveness of biodegradable solvents was evaluated using centrifuge extraction method in this project. It was found that biodegradable solvents were less effective in extracting asphalt compared to chlorinated solvents such as 1,1,1-trichloroethane. However, despite the fact that the basic chemical compositions of different biodegradable solvents are very different, their effectiveness in determining asphalt content and aggregate gradation was found to be about the same. Furthermore, limestone aggregates, which have a much higher percent absorption, were found to yield a much lower extracted asphalt content compared to pea gravel aggregates. Other variables such as solvent dissolving time, solvent rinsing frequency, water rinsing frequency, etc., were also found to affect the extracted asphalt content and aggregate gradation.