The search giant has arranged an event for journalists Thursday at its headquarters in Mountain View, California, just days after rumors circulated that the code might soon be released.
When Google announced it was building its own Linux-based operating system, it said it would release the open-source code at the end of this year. It has said Chrome will be designed initially for netbooks, with the first devices hitting the market in the second half of 2010.
Branching out into the operating-system market could ultimately help Google find new revenue streams, since it is almost entirely reliant on search advertising.
The Chrome OS could also pose a threat to Microsoft, which worked hard to gain its share of the netbook market, which was initially dominated by Linux.
Google has said it is building Chrome because the market needs an OS built specifically for the Web. Most of Google's non-search activities are Web-based applications, such as Google Docs, Gmail and Maps.