Microalgae　is　becoming　a　promising　candidate　for　biofuel　production　and　energetic　lipid　production,　which　urges　the　need　to　develop　efficient　methods　for　improvement　of　the　lipid　production.　In　this　study,　the　neutron　irradiation　was　employed　to　improve　lipid　production　under　different　dosage　irradiation.　Effects　of　different　dosages　(No.1:　8.14　x　10(9),　No.2:　5.64　x　10(8),　No.4:　9.42　x　10(7)　n/cm(2))　were　compared　by　investigating　associated　algae　cell　growth,　total　lipid　production,　metabolization　and　enzyme　activity.　Dosages　No.2　and　No.4　improved　the　lipid　content　without　negative　influence　on　the　growing,　whereas　irradiations　shortened　the　period　of　biomass　accumulation.　The　neutron　irradiation　in　No.2　accelerated　the　synthesis　of　lipid　from　the　carbohydrate　transition　process.　In　addition,　the　neutron　irradiation　not　only　increased　the　total　lipid　production　by　20%　but　also　speeded　up　the　reaction　rate　to　reach　the　maximal　total　lipid　production　in　28　days.　Our　results　can　provide　a　better　understanding　of　the　lipid　production　in　microalgae　Chlorella　sp.　by　neutron　irradiation,　which　are　critical　for　evaluation　of　neutron　irradiation　based　technologies　for　the　sustainable　and　renewable　biofuel　production.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.