If Katherine really loves Stephan why is she with so much guys in the show??

Because she's Katherine... she likes to mess with people. And she's with Mason just because she wants something from him...

Ever heard of having the best of both worlds?

Cause she doesnt really love him!
She doesnt even know what love really is! In my opinion she is a selfish bitch! (No offence to her fans)

she's just using them...but it seems to me katherine does love stefan so much...if she doesn't y would she bothers to hurt ppl's tht relate to elena... well cause its a warning to elena & stefan to away each other...n y she still wants stefan even stefan tried to kill n warned her .. =/

They need her for her masterplan.

She need a wirewolf for something, so she seduced Mason, because she can't do the eye trick on him. He was her little puppet.

She says she loves Stefan and I believe that's true and that her feelings are real. Although, She was with Damon only because she was extremely attracted to him...

And because she lost a wirewolf, she used Matt to "make her a new wirewolf", by that I mean, to get Tyler in a fight.

Maybe she loved Stefan but she could not have been alone for so many years! she's "alive" and has almost all needs that human has :)) and she's Katherine, of course... she was simply using them in all ways..