If she manages another week at number one she'll tie the record set by Prince & the Revolution's Purple Rain soundtrack in 1984 and 1985.
Adele's album was the biggest selling album of 2011 and it's the leader in 2012 as well, with over two million sales since 1 January.
The year's second-highest selling album, Whitney: The Greatest Hits, stands firm at two, while Kid Cudi's alternative rock collaboration WZRD debuts its self-titled album at three.
Houston and Adele dominate the rest of the top 10 - the late soul star's The Bodyguard soundtrack and Whitney Houston album are at five and 10, respectively, while Adele's 19 stays put at seven for a second week.