How can I find out who claim me as a dependent without my permission

To claim you a dependent, no one needs your permission. If someone can claim you dependent, then you can not claim your own exemption. Read: Your U.S. Tax Return: Filing Requirement for a Dependent (http://taxipay.blogspot.com/2008/02/filing-requirement-for-dependent.html)

If you feel someone was not eligible to claim you, then you should file your own return and claim your own exemption. Then IRS will figure out who must amend the tax return.