The use of non-food biomass for bio-oils production appears to be an important trend for renewable energy in China. Biomass, in the form of marine macro-algae, is becoming popular among new renewable energy sources. Fast pyrolysis is one of the most important thermal conversion processes from biomass to bio-fuel. In this work, the marine green tide macroalgae Enteromorpha prolifera was converted into bio-oil by fast pyrolysis in a free-fall reactor at different temperatures ranging from 100 to 750°C. The bio-oil obtained was analyzed by elemental, gas chromatography-mass spectrometer, and Fourier transform infrared spectroscopy analysis. The results showed that the average heat value was 25.33 MJ kg−1 and the oxygen content was 30.27 wt%. The results suggested that E. prolifera presents as a good bio-oil feedstock candidate.