Hi.
I have directory but i dunno how to announce it to the other webmasters.

First off, you need to get it listed in other directories in the appropriate sections.

After that, you might consider hanging out in places where Webmasters hang out - like WebmasterWorld. By being an active member in a community, folks tend to learn about you.

After that, you might even consider springing a few bucks on some PPC advertising to show yourself in front of likely users.