Two ways:
1. If you have pretty permalinks, look at a category page on your blog by clicking on a category link, or whatever you have to do to show the normal page for just one category. Then append “feed/” to that URL.
2. If you’re not using pretty permalinks, use the homepage of your blog (like ht tp://yourblog.com/blog ) and append “?feed=rss2&cat=X” where X is the category id number.
If you want to do this programmatically (in PHP), use the get_category_rss_link() function. It’ll be something like this:
get_category_rss_link(true, $catID, ”);
The true makes it actually show the link (use false to not show it and just return it to you). The catID is the number of the category. The last bit there is not currently used and so it doesn’t much matter what it is. This function works regardless of your permalink settings.