Hii work in model and prepare dwg on 1:1. now i want to show in layout with diff scale in different v ports. there is any command  to show same text height on layout in all v ports?

Salam,
 
Annotate-Text is your need...
 
regards,

Thanks for reply.can you explain how i apply?

Look in your AutoCAD Help file.  The topic name is "Create Annotative Text".  This method involves applying different annotative scales to text objects.  Annotative scaling can also be applied to blocks, hatch patterns, and dimensions.