Abstract: By the research of in-vitro culture of pollens, and by the germination and growth of pollens on the styles, the results were that: 1. The germination ratio of pollen of autotetraploid watermelon was low by self-pollination;2. The growth of the pollen tubes in styles was slow;3. During the germination and growth of pollens, there were some abnormal phenomenon: the blinding of pollen tubes, the swelling as balls at the topes of pollen tubes, and two-tube from one pollen. By the determinations of endogenous hormones, the reasons of above abnormal phenomenon were explained as: 1. The content of zeatin-nucleoside in the female organs and pollens of autotetraploid watermelon was too high;2. The ratio of auxins (IAA and GA3) to growth inhibitor(ABA)was low;3. The results also affected by the reaction between pollens and styles.

Key words: Autotetraploid watermelon, Pollen, Female organ, Endogenous-hormone