I was to suggest you about taking the CMOS battery out for couple of seconds but since you've tried it already I would suggest to contact Asus Support for more information about BIOS passwords or it could be a HDD Master password rather.
thanks. I will try to contact asus support for this problem. I have contact local support but they don't know master password for this laptop. They said maybe the bios chip that soldered on mainboard is broken. Because its suddenly ask bios password , I'm not setting any password before