Arthrospira (Spirulina) is cyanobacteria that used as protein–rich health food for a long time. The potential health benefits of Arthrospira associated with antioxidant, immunomodulation, anti–virus and anti–cancer effect, which are mainly due to three bioactive constituents such as phycocyanin (a biliprotein pigment), the sulfated polysaccharide spirulan and polyunsaturated fatty acid (gamma–linolenic acid: γ–GLA). The objective of this study is to optimize the environmental growth factors for maximizing the biomass concentration and productivity of Arthrospira under the photoautotrophic cultivation in a microalgal culture tube. An optimization of the algal biomass production involved experiments that were statistically designed using the Taguchi method. Six factors varied at either three or two levels, which were as follows; three light intensities (klux), three initial culture pHs, two strains of the cyanobacteria, three concentrations of Zarrouk’s medium (%), three rates of aeration mixed with 1–2% v/v carbon dioxide (vvm) and two temperatures (°C). The optimal conditions obtained from this study help maximizing the biomass cultivation of Arthrospira with using the Zarrouk’s medium.