Hey, Im have begin to use router OS.
I wonder how can i make that its only peppol whit the right ip and the right mac, that can use the router?

use static arp - you will need to enter mac ad ip addres pair, and only these will be valid to connect to your router

Before that you should enable your interface with ARP enable.

http://www.mikrotik.com/testdocs/ros/2.9/ip/address.php

For more information.

Rafiq...