The pirate theme manga, One Piece get the Guinness World Record for the Most copies published for the same comic book series by a single author.
The record sets from December 1997 to December 2014 issue of the Eiichiro Oda manga that has total 320,866,000 copies printed.
As we know, One Piece manga is also the best seller manga in Japan for the year of 2009, 2010, 2011, 2012, 2013, 2014.
The announcement for the record also published on the official website for the One Piece manga.
Since 1997 until now, the manga has total 77 volume book and published in more than 30 countries.
Source: Guinness World Record , ANN