In this paper, we investigate Young's modulus of Si nanofilms and Si nanowires under surface reconstruction with
different temperature range from 100K to 800K by Molecular dynamics simulations. Young's modulus is calculated
from energy-strain relationship. The results show that the Young's modulus of Si nanofilms decreases as temperature
increases. The temperature effect on Young's modulus of Si nanowires also could not be ignored. Surface effect on
nanostructures is more significant than on macrostructures, and Si nanostructures are more sensitive to heat.