You must mean that the clutch is not disengaging?? If that's the case, it sounds like the bike's been sitting. If so, the plates are just stuck together. Go start it and push it, hop on and kick it in gear. Go through a few shifts, use the clutch, they'll free right up.
If you're talking about the bike creeping forward in gear, and the clutch not fully disengaging, try Rotella 5w40 oil in the gearbox, or, better yet, Amsoil 0w40 motor oil.
If none of that gets it for you. I'll bet the tines on your clutch basket are worn. Pull the clutch plates out and run your fingers up and down the tines, or just look at them, they should be perfectly smooth, with no dents or "ripples." If you've got "ripples" it's clutch basket time.