How long can we wait to file I-485 after approval of I-140?

If My I-140 is approved and my priority date is eligible to file I-485, but I decide to postpone the filing of I-485, How long can I postpone it? Is there a requirement that we should file I-485 in a certain period after the approval of I-140?
Thanks.

所有跟帖： 

• 回複：沒有嚴格規定，一般半年左右就認為你自動放棄 -radiology- ♂ (0 bytes) () 08/31/2007 postreply 10:15:07

• 回複：回複：沒有嚴格規定，一般半年左右就認為你自動放棄 -Question100- ♂ (58 bytes) () 08/31/2007 postreply 12:00:14

• 為何要postpone呢？申請140不就是為了進一步申請485嗎？ -小燕南南飛- ♀ (94 bytes) () 08/31/2007 postreply 11:13:44

• 回複：為何要postpone呢？申請140不就是為了進一步申請485嗎？ -cocoine- ♀ (68 bytes) () 08/31/2007 postreply 11:14:58