A conditional permanent resident receives a green card valid for 2 years. In order to remain a permanent resident, a conditional permanent resident must file a petition to remove the condition during the 90 days before the card expires. The conditional card cannot be renewed. The conditions must be removed or you will lose your permanent resident status.
For more information, see the “Remove Conditions on Permanent Residence Based on Marriage” or “Remove Conditions on Permanent Residence for Entrepreneurs” links to the right.