Fluorescence microscope severed as a tool to study the pollen tube growth after crossing between different ploidy levels of Dianthus caryophyllus.Capsules setting rate,planting percent and index of compatibility were calculated.Chromosome counts were carried out in the hybrid progeny.The result shows that:pollen of ‘Zhenzhufen’ and ‘NH6’ germinated after 2 h and callose response was found in pollen tubes.Stylar cannal have callose response in 2 h after pollination.At 4 h,pollen tube tips were found in the style middle,callose response was found in pollen tubes.Some of the pollen tubes reached the base of the style after 6 h.Pollen tubes increased at the base of the style after 17 h,pollen tubes has reached the ovary,which has induced callose response.Fertilization of ovules was noticed from 17 h to 24 h after pollination,and the percentage of presumed fertilized ovules was very low.No seedlings were obtained in the ‘butterfly’（2n=60）בZhenzhufen’（2n=30）,three seedlings which were tetraploid were obtained in the ‘butterfly’（2n=60）בNH6’（2n=30）and revealed that the plants were possibly producing unreduced (diploid) gametes.