Can somebody tell me the right and only way to get position and size
information of Visio shape ...

You don't say exactly what the final info is that you want, however...

Bear in mind that the Width/Height cells establish a "frame of
reference" for the shape, with 0,0 in the bottom left corner, and W/H
determining where Visio will show resize handles and dotted green
outline, and how VIsio will snap shape to grid.

Many shapes are designed so that their geometry is entirely within this
box. Others (such as Triangle) have geometry that extends outside this
box.

Shape location is determined by combining LocPinX/Y (position of "pin)
in shape's frame of reference) with PinX/Y (location of pin in parent
(ie: page or group) frame of reference.

This is described in some detail in DVS.

Graham

The final info i need is the position and size for ALL shapes:

With some shapes the 'Shape.Cells("Width/Height")' properties give
correct values and 'BoundBox()' function give wrong values, and some
shapes the 'Shape.Cells("Width/Height")' properties give wrong values
and 'BoundBox()' function give right values

I need 1 way to get position and size for all kind of shapes

Please identify or describe examples where you feel Width/Height or
BoundingBox are wrong. It's my belief that these cells/properties always
function as advertised, and that it may be you have expectations of
these that are not what' advertised.

Graham