Abstract: Taking Holland double Lily ′Carolina′ as material, the photosynthetic indexes and plant growth were researched by inoculating potted with Sphingobacterium (SN-2), Acinetobacterium (BG and XG), Chryseobacterium (F) and 4 mixed PGPR strains under low light conditions. The results showed that with 70% shading condition, there were some differences on promoting photosynthetic characteristics and growth of ′Carolina′ which inoculated different strains before and after flowering, the maximum net photosynthetic rate (P_max), light saturation point (LSP) and apparent quantum yield (ϕ) of plants were significantly increased by inoculatingwith XG, SN-2 and HH compared with the control, while the effect of mixed inoculation of HH on ′Carolina′ was better than that of single inoculation with XG and SN-2, which indicated that there may be an interactive effect among different strains, but the growth effect was not obvious by inoculating F and BG strains, which may be related to light intensity. In addition, the SPAD content and plant height of ′Carolina′ were significantly increased by inoculating with XG, SN-2 and HH, especially the effect of HH on plant height was obvious. HH and SN-2 promoted the flowering time of ′Carolina′ to be 3 to 7 days earlier than the control, and XG followed.