To reveal the global regulation of photosynthetic electron transport (PET) in shade plants, the changes inchlorophyll a fluorescence induction kinetics (CFI) curvesproteomics were investigated using Hostavarieties. There was a significant difference in CFI curves between Hosta Fire Islandother varieties (such as Hosta SumSubstance) grown under weak light. Weak light induced the appearance of the W phase of CFI curves in the two varieties, which was consistent with a clear decrease in the oxygen-evolving complexa large upregulation of photosystem (PS) II proteins. In Hosta Fire Island, the O-J rise of the CFI curves increased faster under weak light than under appropriate light,this was not only accompanied by a large upregulation of the PS II protein but also a great downregulation in cytochrome b(6)/f, plastocyanin,PS I. Moreover, weak light resulted in a considerable increase in photosynthetic rateRubisco abundance in HostaFire Island, yet the non-photochemical quenchingabundance of CP24 declined significantly. By contrast, weak light had fewer effects on these parameters in Hosta SumSubstance. Therefore, we suggest that thePET is mainly affected by the abundance of PS II, oxygen-evolving complex, cytochrome b(6)/f, plastocyanin,PS I in Hosta plants grown under weak light; meanwhile, the improved photosynthetic capacity under weak light was mainly related to the enhancement of light energy absorptioncapture of PS II as well as theincrease in the abundance of Rubisco.