1. My J1 Visa expired and I have renewed I-2019 in USA. Now, the expire date of I-2019 is June 2017. Can I go back to China after I submit I-140 application? Will I be rejected J1 Visa when I come back to USA because of my I-140 application?
2. Should I change to H1B Visa when I-2019 expire (expire date : June 2017) and before I485 submission?
1. Yes, there is a possibility that you will be unable to get a new J-1 visa stamp after filing the I-140. The J visa category only permits non-immigrant intent and the filing of an I-140 demonstrates immigrant intent, to some extent. You may be able to get the J visa stamp, but there is a chance that the consulate will deny your visa stamp application based on your pending I-140. We recommend that you get your new J visa stamp before filing the I-140.
2. It is up to you. You do not need to change to an H-1B visa before you file the I-485.