This study aimed to stimulation of some environmental factors (pH, temperature, and herbicide) on nutritional content of Chlorella vulgaris algae. The concentration of protein, carbohydrates and lipids and chlorophyll in control were 62.20%, 12.35%, 4.4 %, 1.6 mg/100 ml respectively. Also, the study showed that pH 8.5 was the most appropriate to produce the highest content of chemical compounds (protein, carbohydrates lipids, total energy and Protein digest rate Protein and chlorophyll (62.11%, 13.6%, 3.8%, 488%, 84% and 2.0% respectively). The temperature 35°C was the most appropriate and gave the highest content to most of the studied compounds. But, an exception from that of unsaturated fatty acids reached 22.39% total lipids. The temperature 35ºC is the most appropriate and gave the highest content of the majority of compounds studied. The results showed that the use of the herbicide (Atrazine) affected negatively on all studied nutrition.