Hello Jay He,
Here's info I found helpful for a 4.x install. (quoted from: http://xmlsoft.org/FAQ.html#Installati )
5. I can't install the libxml(2) RPM package due to failed dependancies
The most generic solution is to refetch the latest src.rpm , and rebuild it locally with
rpm --rebuild libxml(2)-xxx.src.rpm
if everything goes well it will generate two binary rpm (one providing the shared libs and xmllint, and the other one, the -devel package providing includes, static libraries and scripts needed to build applications with libxml(2)) that you can install locally.
Hope this helps. If not, you might try posting more information about your operating system etc.