What airline are you flying from HKG to SFO? From SFO to JFK? Are both flights on a single ticket, or did you buy separate tickets for each flight? Are you checking bags, or only taking carry-ons?
You will have to clear U.S. Customs and Immigration upon arrival at SFO, and then have to clear security to get to your SFO-JFK flight. If you only have one hour between flights, there is a good chance that you will miss your connection. And if you have checked baggage, you will almost certainly miss your connection.
What airline are you flying