By default CentOS does not support the 'NTFS' file system, if you are tying to mount an NTFS file system  you will  need to have installed correct RPM package

#  wget  packages.sw.be/rpmforge-release/rpmforge-release-0.3.6-1.el5.rf.i386.rpm

# rpm -Uhv rpmforge-release-0.3.6-1.el5.rf.i386.rpm

warning: rpmforge-release-0.3.6-1.el5.rf.i386.rpm: Header V3 DSA signature: NOKEY, key ID 6b8d79e6
Preparing...        ########################################### [100%]
1:rpmforge-release  ########################################### [100%]

#  yum install fuse fuse-ntfs-3g dkms dkms-fuse

Make a directory for mount a file system to /mnt/usb
 
# mkdir /mnt/usb

# fdisk -l

Disk /dev/sda: 1999.8 GB, 1999844147200 bytes
255 heads, 63 sectors/track, 243133 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          64      514048+  83  Linux
/dev/sda5           14902       15921     8193118+  83  Linux
/dev/sda6           15922      243133  1825080358+  83  Linux

Disk /dev/sdb: 1000.2 GB, 1000204885504 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1      121602   976759808    7  HPFS/NTFS

Execute the mount command
 
# mount -t ntfs-3g /dev/sdb1 /mnt/usb/

Open the mounted directory /mnt/usb
 
# cd /mnt/usb/

# ls -al
drwxr-xr-x 39 root root       4096 May 11 09:34 .
drwxr-xr-x  5 root root       4096 Jan 11 09:34 ..
 

Now the ntfs partition mounts perfect.
 
#  df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda6             1.1T  179G  880G  12% /
/dev/sda5             6.6G  146M  6.1G   2% /tmp
/dev/sda1             587M   43M  519M  10% /boot
/dev/sdb1             932G  781M  931G   1% /mnt/usb

You will need to unmount the partition,
 
#  umount /mnt/usb