If you are in valid H-1B status, and plan to return on a valid H-1B visa (or H-4 visa), then yes, you can travel.
Otherwise, you must apply for an advanced parole document with your I-485. The application is form I-131. You must wait to receive this document before you leave the country, otherwise your I-485 application will be considered abandoned by USCIS. It takes 2-5 months to get your advanced parole document, and now possible even longer because of higher application volume.
Thanks jk0274.
i have to go for my H1-visa stamp at mexico or canada in month of july.In that case also no problem.
Or i have to wait till receipt number.
Coz i came to know that till receipt number comes we are not supposed to leave US