There　is　growing　interest　to　produce　fuels　from　algae,　namely　the　third　generation　biofuel.　Galactose　and　glucose　are　basic　chemicals　for　many　red　macroalgae,　but　fermentation　of　the　mixed　sugars　may　suffer　significant　glucose　repression　using　yeast.　Therefore,　another　fermentation,　acetone-butanol-ethanol　(ABE)　fermentation　of　the　mixed　sugars　was　studied　using　Clostridium　acetobutylicum　and　Clostridium　beijerinckii.　Both　strains　can　use　either　galactose　or　glucose,　and　showed　an　optimal　pH　at　~　5.0.　Co-fermentation　of　the　mixed　sugar　showed　simultaneous　consumption　of　glucose　and　galactose,　and　exhibited　solvent　production　of　4.19　and　4.57　g/L　using　Clostridium　acetobutylicum　and　Clostridium　beijerinckii,　respectively.　The　fermentation　can　become　more　industrially　practical　if　improvement　in　galactose　consumption　can　be　further　improved　in　the　future.