Abstract: Leaves are the main places for photosynthesis. Through photosynthesis, the energy fixed by photosynthesis is used for respiration consumption and assimilation, and the biomass in leaves is allocated at the same time of material production. This allocation is not a proportional change in biomass between stalks and leaves, but an allometric growth relationship between stalks and leaves, that is, the balance between stalks and leaves, due to the influence of their own and external factors. At present, there is no review on the response of intra-leaf biomass allocation strategies to life forms and leaf traits. This paper mainly discusses the response mechanisms of intra-leaf biomass allocation to different life forms, leaf types, leaf sizes, leaf shapes and leaf water content. Several aspects that need to be further studied in the future are proposed: (1) Explore the relationship between all or part of the supporting components and intra-leaf biomass allocation, and reveal how the supporting structure of different proportions affected the leaf biomass allocation strategies, and what kind of 'role' each supporting structure played in leaf biomass allocation; (2) Explore the relationship between phyllotaxis and biomass allocation, and reveal how the intra-leaf biomass was allocated during the carbon gain process of photosynthetic components under different arrangement modes, and how the leaf water and nutrient transport process under different arrangement modes affected the intra-leaf biomass allocation. (3) Explore the relationship between petiole and other supporting structures and leaf traits; (4) Explore the range of leaf economic spectrum (LES) and reveal whether LES includes the relationship between leaves and petioles.