More and more Western artists are officially releasing music in China but albums face the official state censors before being released which sometimes results in tracks being cut from the final runnning order. Famously, the Rolling Stones were banned from playing certain songs when they came to China ( see the BBC report from the time here ) and the same songs were removed from the band's compilation '40 Licks' in its Chinese version. Tracks being removed from albums is by no means uncommon in China today and Gorillaz are not the only artists to have encountered this problem.
It's hard to get information about Chinese releases on the internet but thanks to an ebay seller the tracklisting of some of Gorillaz' recent official releases in China has been revealed. D-Sides (check the listing here ) has Hong Kong and Happy Landfill removed from CD1 (Hong Kong no doubt for the potential political overtones, Happy Landfill possibly for the use of the word 'shit' - although the Chinese censors do not give official reasons for their cuts) whilst all three versions of Kids With Guns were removed from CD2 (presumably the censor objected to the association of kids with guns). The Chinese do get a free poster with the album, however! Demon Days Live has also been officially released in China (check out the listing here ) and features a similarly cut tracklisting ( more of the live visuals were cut than the performances. The full list of cut songs is: 'Intro', 'Kids With Guns', 'O Green World' and 'White Light').
Gorillaz' first official release in China was the album Demon Days, promoted with a special press conference in Beijing in September 2005 (Gorillaz-Unofficial's coverage from the time here ). It is not known which tracks were removed, if any, from that album.