The present invention relates to a composition for skin external application containing a pine root extract. More specifically, the composition for skin external application according to the present invention contains, as an active ingredient, a pine root extract which shows various effects, including eliminating free radicals, protecting the cell membrane from damage by UV radiation, inhibiting the production of reactive oxygen species caused by UV radiation, inhibiting the reduction in the expression of superoxide dismutase (SOD) and catalase caused by UV radiation, stimulating the production of HSP70 to protect cells, inhibiting MMP-2 biosynthesis caused by UV radiation, inducing the expression of SIRT1 gene that restores DNA damage, and inducing the expression of LMNA1 gene that maintains the structure of the nuclear membrane. Ultimately, the composition of the present invention prevents skin aging.