Boron neutron capture was used to treat productive strains of Chlorella and the effects of neutron flux together with radiation time on growth of Chlorella vulgaris were studied. The results showed that the growth rates, chlorophyll fluorescence parameters Fv/Fm, yield, Chlorophyll content, and fatty acid content increased significantly with suitable neutron flux(7.5×108−7.5×109 cm−2?s−1) and radiation time(30−60 s), while the protein content significantly decreased. The neutron irradiation could affect the genetic material of Chlorella, which has a positive effect on selecting productive Chlorella strains.Cited