To amend the Internal Revenue Code of 1986 to permanently extend the 15-year recovery period for the depreciation of certain leasehold improvements and to modify the depreciation rules relating to such leasehold improvements for purposes of computing earnings and profits.

Leasehold Improvement Depreciation Act of 2007 - Amends the Internal Revenue Code to: (1) make permanent the accelerated depreciation of qualified leasehold improvement property (i.e., a 15-year recovery period); and (2) modify the rule for determining the adjustment to earnings and profits for depreciation of such property.