since ive synced my i mac pro ive lost all contacts on my iphone 4

Hi emmafromsutton coldfield,

Welcome to the Support Communities! Have you been using iCloud to keep your contacts synchronized between your iPhone and your Mac? If so, the troubleshooting steps in this article may help you turn that feature back on.

Get help using iCloud Contacts - Apple Support
http://support.apple.com/en-us/TS3998

iOS

After each step, check to see if the issue still exists.

Restart your device

Hold down the Sleep/Wake button, then drag the slider when asked to power off. Turn your device back on.

Make sure that iCloud Contacts is on

Tap Settings > iCloud on your iPhone, iPad, or iPod touch and make sure that Contacts is on.

Update your iOS device

Make sure that you're using iOS 5 or later. To see your version, Go to Settings > General > About > Version.

If your issue continues, install the latest version of iOS that's supported by your device.

Check your Internet connection

1. Try to go to www.apple.com in Safari. If you can't connect to the Internet, your iCloud contacts won't update in the Contacts app. You can get help with your Internet connection.
2. Open a secure website from your iOS device to see if you can access ports 80 and 443. Contacts requires access to port 443 to push updates to and from the iCloud Contacts servers.

Refresh your contacts

If recent changes don't appear in Contacts on your iOS device, try refreshing:

Open Contacts, tap Groups in the upper-left corner, then swipe down to refresh the list of groups.

Check your settings

Make sure that your device is set to display iCloud contacts:

1. Open Contacts and tap Groups in the upper-left corner.
2. Make sure All iCloud is selected.

See if a contact is stored with iCloud or another service, such as Google or Yahoo:

1. Open Contacts and tap Groups in the upper-left corner.
2. Deselect the All [account] option for any third-party, such as Gmail or Yahoo.
3. Make sure All iCloud is selected.
4. View your contacts. If the contact isn't visible, then it exists in a third-party account.
5. You can import the contact from a third-party service into iCloud. iCloud won't sync contacts that are associated with a different service.

You need to make sure that iCloud is your default account for Contacts:

• If you want new contacts to appear automatically on your devices.
• If you're syncing contacts with multiple accounts on your device (iCloud, Gmail, Yahoo) and recent changes to Contacts on your iOS device don't appear on your other devices.

See if iCloud is your default account:

1. Tap Settings > Mail, Contacts, Calendars.
2. In the Contacts section, tap Default Account.
3. Make sure iCloud is selected.

Restart Contacts

Close and restart the Contacts app on your iOS device:

1. Double-click the Home button to see your open apps.
2. Find the Contacts preview screen and swipe it up to close the app.
3. Press the Home button to return to your Home screen.
4. Wait a minute, then reopen the Contacts app.

Turn iCloud Contacts off and back on

1. Tap Settings > iCloud.
2. Turn Contacts off.
3. Choose Keep on My [device].
4. Wait a few minutes, then turn Contacts back on.

I hope this information helps ....

- Judy