Why is my CPU usage so high playing minecraft?

When i run Minecraft my CPU usage bumps up from 10 to
50-60% it used to only be at 20-35% and now javaw.exe *32
Memory(private working set) is at a high 295,00k+ at times, it used to be 110,000k-150,000k

I also just cleaned my CPU to see if it made any difference, but nothing has changed(i do not know if it would help or not but i did it anyway)

I just want to know if this is normal, if not please help D

That sounds fine, there have been loads of reports of Minecraft running very slowly with certain updates.
Try using Optifine to see whether that helps with optimisation, but I'd say that isn't excessive.

http://optifine.net/...t/home.php

Its normal, minecraft uses pretty much all CPU and little GPU power to run. If your PC is good, limit your FPS to around 60 in game, it will cause less stress and less usage of your CPU (If you press F3 and shift or control, its one of those, it will show you what's using your CPU in game). But its completely normal, some computers go up to 90% CPU usage and there fine.