Abstract: Following interspecific hybridization between Actinidia chinensis var. diliciosa‘Xuxiang’and A. longicarpa，pollen tube behaviour among different crossing combinations was determined using fluorescence microscope，difference in fertilization process and embryo development were observed by conventional paraffin sectioning，and fruit-setting rate and hybrid seed quantity were investigated as well. The results showed that the pollen grains of A. longicarpa which is used by interspecific hybridization germinated and grew on the papillate stigma of‘Xuxiang’，but the pollen tubes grew slower than those of the control，wave-like pollen tubes，growth stop and random deposition of callose along pollen tube wall were observed. Fertilization process delayed，embryo grew abnormally and the fruit-setting rate of interspecific hybridization was lower. The seed number in fruit was less than that of introspecific hybridization or open pollination，but there was no obvious difference in the quality of regular seed among crossing combinations.

Key words: Actinidia diliciosa, A. longicarpa, interspecific hybridization, pollen tube behaviour, fertilization, seed