Abstract: Observed the process of fertilization in Hemerocallis citrina Baroni in detail by means of paraffin wax. The main results are as follows: 1. After artificial pollination 1 - 2 hours, pollens germinated at the top of stigma, growing out pollen tube, where only generative cell can get into. 2. Pollen tube prolongs in
stylar canal for 20 - 22 hours, in concomitant with generative cell dividing into two sperms. 3. Pollen tube prolongs on the surface of axile placenta in locule for 2 - 4 hours. 4. After artificial pollination 26 - 28 hours, pollen tube get into one of synergids, and releases two sperms. 5. It takes 4 - 6 hours to egg-sperm fusion, and then bring out zygocyte. 6. The formation of primary endosperm nucleus results from 2 - 4 hours’egg-secondary nucleus fusion. 7. The duration of the whole fertilization is 29 - 36 hours from pollen germination to the formation of zygocyte. 8. After artificial pollination 39 - 48 hours, zygocyte begins to divide. 9. Discussed the significance of the result of study to genetic breeding and molecular breeding.

Key words: Hemerocallis citrina Baroni, Double fertilization, Pollen-tube pathway