Q: backing up icloud if phone broken

If you don't have a backup, then there is no source to restore all your data from.  If you were syncing data with your iCloud account you may be able to restore the synced data by signing back into your iCloud account in Settings>iCloud.  You can check on icloud.com from your computer to see if any of your data is there.

iCloud also keeps your last 3 backups, so you may have an older backup you can restore to before your pone was broken.

You can also sync back any iTunes media in your iTuens library.  Finally, you may be able to redownload purchased media as described here: http://support.apple.com/kb/ht2519.

Camera roll photos (and videos) are only stored in the backup, not on icloud.com.  They would be included in an iCloud backup or an iTunes backup, if you have one.  You can check to see if you have an iTunes backup by opening iTunes and going to Preferences>Devices and looking at the backups list.  This shows all available backups.  If you have an iTunes backup containing the photos, it can either be restored to a replacement phone or you can use 3rd party software to extract the photos from the backup (such as iPhone Backup Extractor).

Photo stream photos are held in iCloud for 30 days.  Photo stream photos from the last 30 days can be retrieved by signing into your iCloud account and enabling photo stream on another iOS device or computer.

If your contacts are on icloud.com, they can be synced back to a replacement device by signing into your iCloud account and turning Contacts to On.  Then can also be downloaded from icloud.com by doing the following (from http://support.apple.com/kb/ht4910):

iCloud.com Contacts

1. Go to iCloud Contacts at icloud.com/contacts, and sign in using your iCloud Apple ID and password.
2. Verify you are viewing All Contacts by looking at the top-left of the Contacts address book style interface. You should see All Contacts.
   1. If you are not viewing All Contacts, click the groups ribbon to load the Groups interface.
   2. Then, click All Contacts in the Group interface to load All Contacts.
   3. Click the groups ribbon again to return to the standard Contacts interface.
3. Click the Action (gear) menu, and select Select All. Every Contact should be highlighted after doing this.
4. Click the Action (gear) menu, and select Export vCard.
5. A combo vCard will be created and begin downloading.
   • Safari on OS X will automatically download the combo vCard to your Downloads folder (~/Downloads).
   • Other web browsers, and Safari on Windows, will prompt you about where you wish to save the combo vCard. Choose a location, and save the combo vCard.

ive broken my iphone and I haven't got backup on it but I have Icloud on it is there any way possible if I could back my phone up from my laptop?????

that's right.

Depends on what you mean by  "I have iCloud on"

Are you making automatic backups? Are you syncing various content? Photo? Contacts? Calendars?

There is no ability to use your laptop for backing up or syncing anything with the phone. All of this is managed from the phone, before it breaks.