The organic materials of biological samples, such as lima bean and peanut, were implanted respectively by nitrogen ions with an energy of 100 keV and vanadium ions with an energy of 200 keV. The positron annihilation lifetime spectra of implanted and non-implanted samples were compared with each other especially in r3 and I3. The experimental results showed that before implantation there were many small holes with diameters of 0.48 and 0.7 nm in lima bean and peanut, respectively. After ion implantation, the size of holes would be changed because of organism cross-linking and scission. The effective penetration range of implantation of ions with low energy into biological samples is about 200μm.