The effects of low energy nitrogen ion implantation on Ca2+ concentration and membrane potential of illy (Mum davidii Duch) pollen cell have been studied. The results showed that the Ca2+ concentration was increased when pollen grain was implanted by nitrogen ion with energy 100 keV and dose 1013 ions/cm2. However, the increase of Ca2+ concentration was partly inhibited by the addition of Ca2+ channel inhibitor depending on dose. And nitrogen ion implantation caused depolarization of pollen cell membrane potential. In other words, membrane potential was increased, but the effect decreased by adding Ca2+ channel inhibitor. However, it was still significantly higher than the membrane potential of control cells. It was indicated that the depolarization of cell membrane potential opened the calcium channel on the membrane that caused the increasing of intracel-lular calcium concentration. This might be an earlier step of the effect of low energy nitrogen ion implantation on pollen germination.