Abstract: In this study，low-light sensitive cultivar‘K20’and low-light tolerant cultivar‘Shenfen 16’were selected as materials. The effects of low light on plant height，stem diameter，internode length，numbers of leaves，antioxidant enzyme activity，MDA content and RNA-seq data were analyzed. The results showed that low light inhibited the growth of tomato plants，accompanied with an increase in MDA content and decreases in antioxidant enzyme activities，but the reductions in ‘Shenfen 16’were smaller than those in‘K20’. Furthermore，898 differentially expressed genes（DEGs）were identified in‘K20’and 2 849 DEGs were obtained in‘Shenfen 16’under low light stress. The up-regulated pathway of Kyoto Encyclopedia of Genes and Genomes（KEGG）enrichments in‘K20’were‘protein processing in endoplasmic reticulum’and‘ribosome biogenesis in eukaryote’，whereas the largest amount of DEGs in‘Shenfen 16’were annotated with‘plant hormone signal transduction’and followed by‘MAPK signaling pathway’. These results suggested that low-light tolerant cultivar may increase its adaptation to low light by regulating the biosynthesis of hormones. In summary，low light inhibited the growth of tomato plants，but low light-tolerant cultivar may increase its adaptability to low light by regulating the synthesis of various hormone such as IAA and increasing the activities of antioxidant enzymes.

Key words: Solanum lycopersicum, stress, low light, hormone, transcriptome analysis