I have a AthlonXP 1.6 with 512 of ram DDR and a Radeon 9600XT 128MB.
Will this game run well on my PC?

I'm not an expert on graphix cards or processors, but with a complecated name like that (especially with a version type) you should probably try it out. If you have SBFI you can always ask for it to analyze your computer, and if it's capable of running SBFI it sure as heck should be able to run SBFII just as well.

Yeah I have the first one and I can run with all Settings on High, but I heard that BF2 needs a better PC and I wanted to be sure my PC can run it before I buy it.

You are under the recomended requirments, but above the min. You may have a few problems on the larger maps, ones with many plants, and maps with water.

Requirments link: http://yodashelpdesk.lucasarts.com/faq.asp?sid=185821051228216135029035&pid=1459&pnm=Star%20Wars%20Battlefront%A9%20II&seid=3925&pos=Windows%20XP&top=System%20Requirements&rid=22588)

I would sugges you to get some rams... its good for more than just gaming.

AMD Athlon 1.4Ghz
512MB DDR
Radeon 9600XT

Battlefront II runs great on my machine.