Abstract: The double fertilization process of Passiflora edulis f. flavicarpa Deg. was observed via paraffin sections staining with Haematoxylin and feulgen reaction, and the results are as follows:After pollination, pollen grains germinated soon on the stigma within 30 minutes, and then the pollen tubes grew down the transmitting tissues of the styles. After 6.5 hours, the pollen tubes reached the ovary and grew along inner wall of the ovary. After 7~7.5 hours, the pollen tubes ran through the nucellar beak to the embryo sac and relesed the contents with two sperms.In the most ovules after 7.5~9 hours of pollination, the sperms were attached to the egg cell plasmas membrane, then entered into the nucleus.The sperm chromatin showed dispersion and the male nucleolus appeared.The male and female nucleoli were combined and fused to form a single nucleolus, and the egg cell came to the fertilized.Fertiliztion of polar nucleus is in the same time and similar to the egg cell fertilization.The fertilization of P. edulis f. flavicarpa Deg. is of premitosis type. Dormant period of fertilized egg cells and primary endosperm nucleus was not observed.Cell division take place immediately after fertilization finished.

Key words: P. edulis f. flavicarpa, double fertilization, microscopy