Oracle said in a statement that Google's Android system for mobile phones infringes on its patented Java technology.
Google spokesman Andrew Pederson said the company can't comment because it has not yet reviewed the lawsuit.
Oracle, which makes database software and other technology, acquired the Java computer programming language and related technology when it bought Sun Microsystems. That deal that closed in January.
Java can be used as a platform for building applications for computers, websites and smart phones and other mobile devices.
In its complaint, filed with the U.S. District Court for the Northern District of California, Oracle said Google's Android operating system software consists of Java applications and other technology. As such, it infringes on one or more parts of seven different patents - something Google should know, Oracle argues, because it has hired former Sun Java engineers in recent years.
Oracle also said Google's Android also infringes on Oracle's copyrights in Java.
Oracle is seeking an injunction to stop Google from further building and distributing Android, plus higher monetary damages for willful and deliberate infringement.
Google says about 200,000 Android-powered phones are being sold each day.