(1) Log in to the U.S. Intellectual Property Information Service Network (https://www.uspto.gov/) and click "search for patents" in "Patents";

（2）选择Patent Application Information Retrieval (PAIR)
 

(3) Select Visit PAIR.

(4) Select Access Public PAIR.
 

(5) Enter the application number to query the patent information and legal status of the patent.

(6) Select fees and enter the patent number and application number to query the annual fee information.

U.S. patent annual fees