The shooting happened around 1am on Gears Road.
Deputies say 200 to 300 teens from Westfield, Spring, and Dekaney high schools were at the party.
One partygoer says seven people showed up and were told to leave. That's when at least one or two shooters fired shots from a rifle and a pistol.
One teen is in critical but stable condition in the hospital.
The shooter or shooters are still on the run.
Anyone with information about the identity of the suspect is asked to contact Crime Stoppers of Houston at (713) 222-TIPS (8477).
Crime Stoppers will pay up to $5,000 for any information called in to the 713-222-TIPS (8477) or submitted online at www.crime-stoppers.org that leads to the filing of felony charges or arrest of the suspect in this case. Tips can also be sent by text message. Text TIP610 plus your tip to CRIMES (274637). All tipsters remain anonymous.