The most copies published for the same comic book series by a single author is One Piece created by Eiichiro Oda (Japan) with 320,866,000, copies printed and circulated from December 1997 to December 2014.
One Piece author Eiichiro Oda gave a personal response to this news:
Thank you for the Guinness World Records recognition. Though manga is a form of entertainment to pass time, I am very happy whenever I am told that fans made friends and met their significant other through One Piece. This numerical record demonstrates to me the possibility of just how many people could be connected. I will never forget the gratitude I feel toward the pioneers and supporters of the manga world, as well as my readers, and would like to continue creating work that wouldn’t shame this record.
On the same day, an official certificate ceremony was held in Tokyo and Yoshihisa Heishi, Weekly Shonen Jump‘s Editor-in-Chief, attended on Oda’s behalf. As he accepted the certificate, he expressed that he is very happy that One Piece has become a worldwide success in both name and substance.