Introduction: Helianthus tuberosus L. is main source of inuline in pharmaceutical and food industry. Pharmacological studies of the plant have showed some important therapeutic properties such as anti-diabetic, anti-osteoporosis, anti-cancer and strengthening cardiovascular system, immune system. Material and method: Helianthus tuberosus L., which has been cultivated in Botanical Garden of Medicinal Plants of Drug Research Institute, Monos Group, was used as a research raw material. The aerial and below ground parts of the plants were harvested in September 2020. The content of inulin, the main active ingredient in the plant, was determined by spectrophotometry. Raw materials of the plant were processed in several ways and prepared for further use as a pharmaceutical raw material. Result: Inulin content in Sample 1 was 34.5 ± 0.76%, Sample 2 was 70.31 ± 1.25%, Sample 3 was 78.43 ± 0.44% and Sample 4 was 75.36 ± 1.42%. The inulin content and yield were the highest in samples prepared by heat and cold cutting methods. Conclusion According to the results of appearance, yield, inulin content and moisture contents during the different processings of plant materials, it can be considered that the most suitable method for preparing Helianthus tuberosus L. as a pharmaceutical raw material is the cutting followed by freeze-drying.