QUOTE(daphne2109 @ Apr 22 2008, 10:00 PM)

Do you know if even if you get the US citizenship, can you keep your dual citizenship (where the country of the non- US citizen allows that) without having problem to get back to the USA, and if you stay away from US for a while without presenting the file taxes, (since you haven't worked in US during that time) is still ok to enter US without having problems.
I hope my above question is clear!!!! Tks again!!!!!
Whether you remain a citizen of your old country is a matter of your old country's laws. It's not a problem from the US law perspective. So you can be a dual (or triple, quadruple, or multiple) citizen after naturalization to the US.
However, whether you're working in the US or not, when you're a US citizen, you have to file taxes any time your worldwide income exceeds the limits that require anyone to file taxes. For practical purposes, that probably means you have to file taxes every year, even if all your income came from outside the US. However, in many cases, income earned outside the US is not subject to US taxation, so while you have to fill out the returns, you may not have to pay any tax, or it may be a very small amount.
Failure to file taxes won't cause you to lose your citizenship or be unable to enter the US, but it may cause very serious problems with the IRS when you finally do re-enter, just as it would cause problems for a citizen who remained inside the US and failed to file taxes.