Hi, you can follow this way to do that:
1. In Visio, open a new drawing. Then go to Step 2a if you want to create a new stencil; otherwise go to Step 2b if you want to modify an existing stencil.
2a. To create a new stencil, start by creating a blank stencil (File - Stencils - New Stencil).
2b. To modify an existing stencil, open the stencil (File - Stencils - Open Stencil). Right-click the title area of the stencil, and select "Edit". A red asterisk will appear in the title area to indicate that the stencil is now editable.
3. In your drawing area (or "workspace"), draw the object that you want to add to the stencil. You can use any of the Visio drawing aids to do this - the rectangle tool, line tool, etc. You can also open other stencils that may have objects or shapes you want to use as part of your drawing.
4. If you wish to scale your drawing to specific dimensions, you can use the Dimension Line to measure dimensions of your object. (The Dimension Line is available on the Office Layout Shapes stencil.)
5. Once you are satisfied with your drawing, group all of its parts into a single grouped object. (To do this, select all of it (Edit - Select All); then Right-click; Shape - Group.)
6. Drag the grouped object onto the stencil that you want to add it to. (If you get an error message saying that the stencil is read-only, check that you have opened it for editing per Step 2 above.)
7. An icon for the object will appear in the stencil, with a generic name such as Master.0. To give it a more meaningful name, right-click the object, select "Master Properties", and overwrite the Name field to whatever you wish.
8. Repeat Steps 3-7 for each object that you want to add to your stencil.
9. If you want to rename the stencil, simply Right-Click the stencil title area, select Properties, and overwrite the stencil name.
10. To save the stencil, click on the diskette icon in the stencil title area (or Right-Click, Save in the stencil title area).
At this point, you can use the stencil as you would any other Visio stencil.
The source:http://home.comcast.net/~hchute/woodshop_visio_stencil_howto.htm Answered Apr, 26 2011