Question: i want the assemblies (\*.dll) files for silverlight charting controls
or give me path that where does it stoer when we install the toolkit
in our computer

Answer: 
When you've installed the toolkit you will find the dlls in:-

`C:\Program Files (x86)\Microsoft SDKs\Silverlight\v3.0\Toolkit\Nov09\Bin` 

or on a 32 bit system:-

`C:\Program Files\Microsoft SDKs\Silverlight\v3.0\Toolkit\Nov09\Bin`

The above is obviously for the November 09 release, no doubt as this answer ages the latest release will be in a similarly named folder.

However they should be listed in the .NET tab when you add references.
There should be a toolkit folder under C:\Program Files\Microsoft SDKs\Silverlight\v3.0\ after installing toolkit.