None. USC is not an NFL team. Perhaps you should be asking how many FORMER USC players are in the NFL. The answer to that would be... um... a lot. reggie bush, Carson palmer, mark sanchez, clay matthews(i think)...
1. Reggie Bush
The final rosters for the upcoming NFL season haven't been released yet, so these numbers are current as of the 2013 NFL season. LSU, Miami (Florida), and USC are all three tied with 58 current NFL players.
The USC Trojans
Michigan - 39 USC - 28 This as of 9/20/07
As of 7/9/2012 the Seattle Seahawks have 6 former USC players on their roster. If you check on USC's official website, (http://www.usctrojans.com/sports/m-footbl/trojans-in-the-nfl.html) it shows the number of active former USC players currently in the NFL. However, this website doesn't update very often. I just looked at it, and noticed that they have players from the 2011 season still listed on teams that they no longer play for.
USC, Texas, Florida
Currently, the University of Southern California (commonly known as USC) has the most football players currently in the NFL, with 38 total players in the game.
USC, or University of Southern California has many alumni that continued there football career in the national football league.
Players who are in the NBA that have gone to USC are O.J Mayo, and raptors SG DeMar DeRozan who's having a break out season that's all I know. Feb, 27 2011
As of 2010 Notre Dame had 462 players drafted. USC (Southern California) was second with 461 drafted players
Generally schools are measured by how many "quality" players they produce. But USC, Florida, and Texas produce by far the most averaging 3-4 players a year. That is alot.