Thanks you all!!
For your help, I can do with my system.
I really appreciate your help..
First I booted with cdrom (boot cdrom -sw)..
Then I edited passwd & shadow file.. --> Oops! Password file was corrupted!!
So I decided to erase it and make another one! and, make accounts again..
Then, as you told me, I mounted all my file system.
Maybe, I think it seems foolish of me eraseing all accounts & making new
accounts.. but as for me, there's no way to recover I think.. *.^
Actually, this is my first time, loosing root passwd & crashing my file system..
Would you give me your suggestions making my system more robust?
And thank you in advance..