In the Form 131, there is some information as below,
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If you are in the United States and wish to travel abroad, you do not need to apply for advance parole if both conditions described below in numbers 1 and 2 are met:
1. You are in one of the following nonimmigrant categories:
a. An H-1, temporary worker, or H-4, spouse or child ofan H-1; or
b. An L-1, intracompany transferee, or L-2, spouse orchild of an L-1; or
c. A K-3, spouse, or K-4, child of a U.S. citizen; or
d. A V-2, spouse, or V-3, child of a lawful permanentresident; and
2. A Form I-485, Application to Register PermanentResidence or Adjust Status, was filed on your behalf andis pending with the USCIS.
However, upon returning to the United States, you mustpresent your valid H, L, K or V nonimmigrant visa andcontinue to remain eligible for that status.
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I have valid H1B visa and my 485 is also pending. If it is possible I can go to China for a short period and come back without problem. Thanks a lot for your suggestion!