Amends the Illinois Income Tax Act. Creates an income tax deduction for an amount of up to $50,000 per tax year contributed to a small business asset purchase account and all interest earned on such accounts during the tax year. Provides that a "small business asset purchase account" means an account established by a taxpayer, the proceeds of which are used to purchase property used primarily in Illinois for which a federal income tax deduction is claimed under Section 179 of the Internal Revenue Code. Provides an addition modification for amounts withdrawn from a small business asset purchase account that are not used for qualified purchases. Amends the Uniform Penalty and Interest Act to establish a penalty for improper use of moneys in a small business asset purchase account. Effective immediately.