Problem Solved
Thank you For kamikaze, SirDice and danger.
My problem is solve.
First, i boot freebsd in single user mode then i renamed fstab file with another name, then i maked new fstab file and type manually contains of fstab file with echo.
echo '/dev/ad4s1e /usr ufs rw 2 2' >> /etc/fstab
and what the result?
i got new fstab file. I reboot my FreeBSD, and my FreeBSD boot normally.
Thank You