Occurrence and parallel variation of free indole 3 acetic acid (IAA) and gibberellins (GA3) in different organs of Helianthus annuus L. have been inves tigated at various development stages by the gas chromatography method. The highest concentration of IAA was found in aboveground organs while the IAA concentration in roots was much lower. Genotype variation has also been determined. It has been established that the percentages of free IAA in roots, leaves, inflorescences and flowers were much higher in parent lines than in the F1 hybrid. These data demonstrated a direct correlation between auxins and hybrid vigor. The obtained results demonstrate the spatial (roots, leaves, inflores cences and flowers) and temporal distribution (during various ontogenetic phases) of auxins, which confirm their taking part in polarity formation and indicating dominant centers of activity in sunflower.