Abstract:In recent years, some populations of Cyatheaceae plants in China have suffered from largescale diseases and insufficient seedlings. To explore whether seedling shortage is related to soil pollution, in this study, based on the successful observation of the normal behavior and morphological of Cyatheaceae Sphaeropteris lepifera sperm, we studied the behavior and morphological change regulations of S. lepifera sperm under the stress of lead and cadmium for the first time. The results showed that: (1) Under the stress culture conditions with Pb2+ concentrations of 1.25, 5.00 mg·kg-1 and Cd2+ concentrations of 0.25, 1.00 mg·kg-1, the life span, swimming displacement velocity and rotation frequency of the sperm of S. lepifera decreased significantly compared with the control group. (2) Pb2+ would affect the motility of the sperm of S. lepifera, while Cd2+ would affect the ability of the sperm to distinguish the concentration of female substance and makes sperm lose its direction. (3) The changes of sperms morphology and behavior after heavy metal stress include limitation of sperm extension, flagellum contraction and abscission, sperm nucleus deformity, swelling, degradation, sperm mutual adhesion, reverse movement and autolysis. And the malformation types of sperm under lead or cadmium stress were different. It is proved that the single stress of lead and cadmium with low pollution concentration can significantly affect the behavior and morphology of the sperm of S. lepifera and seriously block the sexual reproduction of Cyatheaceae.