Does my tourist visa get void when applying for green card?

The B1 visa does not get voided automatically just because your mother filed an immigrant petition for you. However, you need to know the consequences of the filing and be prepared. By law, an applicant for a non-immigrant admission to the U.S. must prove that he/she does not intend to become an immigrant in the U.S. (in the agency's parlance, that he/she "has no immigrant intent"). After your mother petitions the U.S. government to let you immigrate to the U.S., you appear to have an immigrant intent; and an immigration inspector at the border can deny you permission to enter the U.S. despite the fact that you have a visa. To avoid being turned around at the border, you will have to convince the inspector that, although you do intend to become a permanent resident of the U.S. one day (when you will have an immigrant visa), you have no intention to stay in the U.S. permanently *now*. There is no established procedure or a list of required documents, but you can be quite certain that your word alone will not be enough. The inspector would want to see some documentary proof of your intent to return to your country at the end of your visit - a return ticket, a letter from your employer confirming that you are gainfully employed and expected to come back on a certain date, documents showing that you left in your country a spouse, children, property, a business, etc. ("demonstrating substantial ties to your own country"). Anything might help - as long as it shows that you will - more likely than not - leave the U.S. at the end of your visit: being listed as a presenter at a conference in another country, running for a local office, admission to a university, etc. One of my clients believes that, of all the documents he brought, a letter from his dentist confirming an appointment for an implant was the one that convinced the immigration inspector that he does not plan to remain in the U.S. So, while there are no guarantees, a thoughtful preparation will increase your chances of being admitted for a visit despite having an immigration petition filed. You might also consider flying to Canada and traveling down to the U.S. by car, bus, or train: this way, if you get denied entry, you will be able to stay in a hotel near the border while your attorney tries to convince the immigration authorities to reconsider their decision (instead of waiting for an outcome inside an airport).