Background: Parsley (Petroselinum hortense Hoffm.) is one of the most famous medical and nutritional herb. Fruits of parsley traditionally used as diuretic, appetizer, vasodilator,... with out any side effects. Also, it is used in cosmetic industry as a deodorant to cure halitosis and in nutritional industry. Objective: Study of microscopical characteristic, extraction and identification of the essential oil of the chemical composition of Parsley seed, is the main aims of this study. Methods: For this research, fruits have seen purchased from the market of Tehran and Identified. Microscopical characteristic will be done using light microscope and extraction of the essential oil will be done with hydro-distillation method using Clevenger apparatus and then identified after GC/MS findings. Results: Endosperm containing crystals of calcium oxalate and oil spots, parts of compact cells of Endocarp, a group of fibro vascular, Epiderm tissue containing fragment of a vitta, were the most fragments of the powdered seed. The total amount of the Essential oil was 1% V/W and the most analyzed compounds were: 1,8 cineol (59.2%)-- phellandren (18.6%)- -pinene (7.6%). Conclusion: There was no difference between the microscopical characters of the powdered seeds of Iranian cultivated Parsley with the cultivated specimen in other country. The absence of two compounds Apiol (aborticide agent) and Miristicin (agent causing euphoria) in Iranian cultivated Parsley is a significant safe character for the using of the Iranian specimen in food and pharmaceutical industries.