Abstract: To clarify the relationship between the response of crown leaves to shade environment and biomass production, five genotypes of Populus×euramericana with different parents planted in two densities (2 m×3 m, 2 m×5 m) were chosen and the biomass production, crown depth, crown width, LAI and photosynthesis light response parameters were investigated. The results are as follows: (1) The response to weak light varied among genotypes. (2) The Genotypes 03-04-97,03-04-111 and 03-04-171 showed a high shade tolerance ability and had the highest biomass production in high density plantation. (3) The shade tolerance of genotypes 03-04-97,03-04-111 and 03-04-171 was different under different plantation density. Compared with the density 2 m×5 m, the crown leaves of middle and lower layer showed higher ability of shade tolerance. (4) The interaction between shade tolerance and biomass varied under different plantation density, the shade tolerance of upper layer had significant affections on biomass under the density 2 m×5 m, however, the shade tolerance of upper and lower layers played an important role in biomass production under the density 2 m×5 m. (5) The shade tolerance was affected by environment and heritability. The light compensation point (LCP) and respiration rate (Rd) of the genotypes with high biomass production was significant lower in 2 m×3 m compared with 2 m×5 m. These results could be used to select genotype for high density and short rotation plantation.