Pollen viability of 11 strawberry cultivars differing of photoperiodic sensitivity was investigated. During whole flowering period, average content of fertile pollen of everbearing fruit cultivars (‘Ostara’, ‘Geneva’, ‘Mara des Bois’, ‘Rapella’) amounted 28.5% and remained at the same level, whereas day-neutral cultivars (‘Selva’, ‘Tango’, ‘Evita’, ‘Irvine’) in third decade of June and July decreased at 35.2% in comparison to May level. Radiolographic analysis of plump seeds of 5 strawberry cultivars confirmed close relationship between pollen fertility and the plump of seeds.