My svchost.exe mem usage is very high in taskmanager how resolve it.and my system is very slow suggest.

svchost.exe Windows process - What is it? (http://www.neuber.com/taskmanager/process/svchost.exe.html)

You may have a virus or other malware.

You can solve this by scanning for adware/viruses using some software, information about virus protection software are in other threads, have a look around.