The distribution and degradation of I-¹⁴C-ABA in apple seeds during stratification was investigated. It was found that total radioactivity of labelled ABA present in the apple seed after 4⁸ h of soaking in I-¹⁴C-ABA solution decreased gradually during the stratification period. The decrease of radioactivity was observed in seed coats and endosperm with the simultaneous considerable increase in the cotyledon and embryo axis. Decarboxylation of I-¹⁴C-ABA was demonstrated and it is postulated as a mode of ABA degradation in apple seed.