Probably the font is first created as a clean version, and then texture is added in Photoshop. The texture is simplified to only be black and white. Select the letter with the magic wand and soften this selection, f.i. with a blur and use this altered selection as a mask for the the texture. There are also other ways to do this, but this seams the easiest to me.

To then create vectors out of this one can either manually trace it in Illustrator or use the autotrace. Results may vary, so one should experiment. If one wants to make this into a font, it should not contain too many nodes, otherwise it will cause problems in use, so one should probably clean it up manually. There are also other applications for tracing, which you could try. To make this into a font, you need a typedesign program, like Fontlab, Fontographer, Typetool, Glyphs or Glyphs Mini. Which one you choose depends on your budget, and the amount of features you want to use.

http://fontfeed.com/archives/tip-the-wornweatheredstamped-look/

Thank you Queneau! your technique works for me :D
here is my result:

Thanks to gegenwind too.

I am glad I could help :-)

I recommended you word pad is best one for that it's easy to use and understand about it from your college or friends. Personally i use deeply it has lot of format you can choose and any one that you require.

Hey in case you're ever looking for more options with this I've used this before: http://blog.spoongraphics.co.uk/tutorials/how-to-make-a-letterpress-text...

Letter press texture is another option to look at.