How to make courtesy letter ? Give an example after meeting courtesy letter ?

The biggest factor is what you are trying to say. Was it after a job interview? Or a sales meeting?

There are many templates and examples available on google.com

Type in "Follow-up letter" or "courtesy letter."

This will get you started nicely.

Dear Sir or Madam,

Please refer to our meeting in your office on December 08, 2011 regarding Construction of Airport.

I am glad and thankful to you for sparing your valuable time with me. I hope that the meeting is converted into a good long lasting business relationship.

I am looking forward for your future communication.

With regards,
Adam Sandlers.