Spirulina, also called blue-green algae, belongs to cyanophyta, Cyanophyceae. Due to the primitive simple cell structure, it is the earliest photosynthetic creature existing for more than 3.5 billion years. As a low-grade creature, they are kind of uni-cellular or multi-cellular protonema, known for its state of being spiral model under the microscope. With no colloid sheath on the surface, it cannot be easily attached by the microorganisms. With bubbles in the cell, it has good floating feature. There is no taper roof for the cell or filament, and the cross wall is not obvious. The top cell is round without incrassation on the shelltface sltell, along with the possibility of mass propagation, thus forming water bloom.

Spirulina is also a kind of photosynthetic autotrophs creature, of which its cell contains photosynthetic synusia (thylakoid), vitamin, crude protein, crude fat, carbohydrate and carotene, etc. Spirulina contains rich protein of about 60-70%, with reasonable amino acid, especially rich carotenoid, vitamin B12, iron and linoleic acid.