im confused !!!!

Yes, he does really hate Zero. I think it's because Zero was able to grow so close to Yuuki, though I'm not really sure myself... ^^;

actually Kaname is jealous of Zero cause Zero can always stays close to Yuki on the other hand he has to keep a distance from to protect her.
So apparently his jealousy sometimes turn into a little bit of hatred.
I am quite sure it happens in most of the ত্রিভুজ loveツ

his jealous of zero since, he can be with yuki all the the time during the first ark, and his agitation began to even grew আরো in the জাপানি কমিকস মাঙ্গা when he learns that some parts of yuki's হৃদয় belong to zero , not half like most of the zeki অনুরাগী think.