Abstract: Taking Micro-Tom tomato as experimental material, the parameters of plant growth, photosynthetic parameters, fruit weight and quality, root morphology, average uptake rate of nutrient elements as well as correlation among them of tomato grown under different supplemental blue light treatments（B:anthesis-fruit mature, B1:anthesis-fruit green mature, B2:fruit green mature-mature） were investigated, in order to clarify the effects of supplemental blue light on tomato growth, fruit quality and uptake characteristics of nutrient elements.The results showed that, B1 treatment effectively promoted growth, fruit expansion, fruit number and fruit weight of tomato, which was consistent with B treatment.B treatment significantly enhanced tomato root growth, but B1 treatment significantly promoted the elongation of taproot, B2 treatment had no effect on tomato root growth.The contents of organic acids in tomato fruits were significantly increased under B1 or B2 treatment, but the content of soluble sugar and vitamin C,and sugar-acid ratio were not affected by supplemental light.The average uptake rate of NO₃-N,PO₄-P,K⁺,Ca²⁺ and Mg²⁺ were significantly increased under B1 and B treatment.B1 and B supplemental indirectly promoted fruit setting, accelerated fruit development and promoted the ripening as well as fruit coloring through promoting the uptake of PO₄-P and K⁺.Therefore, B1 supplemental light treatment could achieve the same effect as B supplementary light treatment, which was better than B2 treatment.Therefore, the light supplementation strategy at can be considered in fruit development stage.Supplemental light at fruit development stage can be considered as a low energy consumption supplemental strategy.