Hi
I run VPN on my MikroTik router and it works greate.
But I wonder one thing if that is possible to create another VPN account and that account only can access to one of the server in my LAN?

Not enough details provided. In general, if you have in mind that several users would connect to a single MT acting as VPN access server and each of them would get an individual set of access restrictions, then yes, this is a routinely used approach, but implementation details vary depending on the VPN protocol used (plain IPsec, L2TP/IPsec, SSTP, ...).

hmm ok, have to look into that
That I use is PPTP but going to read some more about Mikrotik and VPN