I'm Komiljon Sharipov Fulbright scholar from Tajikistan (former Soviet Union country) arrived to US in November 2010, Tajikistan has a tax treaty with US, but when I get my stipend Federal Tax 14 % was withhold from it, how can I return withhold taxes

If you are doing work for which the stipend is being paid, then it is taxable income, hence the 14% withholding.