Nowadays petrochemical-based plastics pose environmental problems because it non-degradable. Biodegradable plastics have been continuous interested because it shows biodegradation and environmental friendly. Polyhydroxybutyrate (PHB) can be produced by cyanobacteria and well accumulated in nutrient limited condition. This work aimed quantify PHB using high pressure liquid chromatography in the cells of such 135 cyanobacteria in Thailand. The cyanobacteria was cultivated in BG-11 medium without nitrogen and add 0.4% acetate for carbon source in the dark 6 days. This culture condition showed the cyanobacteria have been accumulated PHB intracellular. PHB content of Oscillatoria jasorvensis up to 24.14% of cell dry weight (% w/cdw). PHB accumulation was no detectable correlation between cyanobacterial evolution and the high PHB accumulation phenotype. Thus, the high PHB accumulation phenotype might emerge at the later evolutionary process. This result provided fundamental data for PHB contents in 135 Thailand-isolated cyanobacteria under this condition and can be selected cyanobacteria high PHB accumulated used in the production of biodegradable plastics with better properties such as polyhydroxybutyrate-co-hydroxyvalerate in the near future.