HI there is a folder called test..
there are 2 users to access this test folder..

how can i give chown permissions to this directory

Put both users into a group, and assign group ownership for that folder.

So your folder looks like this right now or something like it anyway:

This is how my SAMBA is set:
/home/samba/media

BEFORE ownership changes ->
[server@server samba]$ ls -l
drwxrwxr-x 2 root root 4096 Feb 5 00:19 media

AND after you change the group from root (or whatever group it is to the group you want) it will look like this:

AFTER ownership changes ->
[brendan@SDM samba]$ ls -l
total 8
drwxrwxr-x 2 root group1 4096 Feb 5 00:19 media

(grouop1 being the group which you assign those two users to)
So you would type: chown root:group1 samba (group1 would be your group of the two users.)
chown (owner/user) : (group) (directory/file)
try chown --help or man chown

You may also need to change the read/write settings. I had a similar problem when I first was playing with SAMBA. Make the directory permissions 775 (owner/group/public)