FT-Raman spectroscopy was adopted to investigate the Raman spectrum of Platymonas subcordiformis. The result shows that the optimal experiment condition is making sample lose solvent with centrifuge, exciting laser power set at 360 mW and accumulating 70 times. The main peaks of the spectra are 381-432, 552-556, 611-613, 710, 873, 953-964, 1 108-1119, 1457, 1523-1527 and 2986 cm(-1). They belong to protein, insaturation acid and ester, etc, which are the main composition of Platymonas subcordiformis. The precise measurements of algae Raman spectra could be used for developing a new optical taxonomic methodology to distinguish between different algae species, and a rapid, non-destructive detection way of stress effects.