+1  A: 

Like AnthonyWJones said, this seems like a CSS/HTML question. Once you use XSLT to transform the RSS feed into HTML, it is simply treated (and thus rendered) as a standard HTML document.

My best guess at this point is that you need to put a container (a block level element such as <DIV>) around the description (or the whole document) and specify a width for it that is within the dimensions of the display using CSS.

So something like this should work:

<style type="text/css">
#container {
    width: 90%;
}
</style>
<div id="container">
    // Your XSL code
</div>
Calvin
A: 

I don't know why it does not work. The other thing that I get confused is that I try to test by creating new HTML file, and then add the paragraph with the same number of text, but the text is automatically wrapped within the margin.

So why it does not wrap in XML? Would someone help explain this to me? Thank you

Nguyen Quoc Hung
This isn't an answer. If you want to expand on your question, just edit the question itself. Also, read the comment AnthonyWJones left for you. It would be easier for us to find your problem if you included your CSS in the question.
Calvin