Aspal Buton is natural resources which are owned by Indonesia. One of buton asphalt processed is Retona Blend 55 Asphalt. Due to the abundant stock and have better quality, then Retona Blend 55 Asphalt can be used as subtitute for Pertamina asphalt. Another natural resoutces beside buton aspal, coal also include which are owned by Indonesia. Coal Fly Ash itself has size which is passes sieve number 200 and it has hydrophobic profile. Because of that reason the authors choose Coal Fly Ash as the filler in the concrete asphalt mix and use Retona Blend 55 as the binder. The method of the experiment is using Marshall methode to determine the effect with the use of Coal Fly Ash as subtitute material of some filler. From the test results obtained KAO 6% and with application of filler of amount 3%, 3,5%, 4%, 4,5% a decrease value of VMA, VITM, Marshall Quotient, and Stability. And for VFWA, Flow and Density the value was increase compared to the test object without Coal Fly Ash.