The 14-year-old, who became the youngest ever player to turn out at Augusta, was the only amateur to make the cut for the final stage of the tournament.
The Chinese teenager, who finished the competition on 12-over par, admits that there are a lot of aspect to his game that he needs to work on.
"I think the first couple of rounds I played pretty good; I felt a little bit tired today," said Guan.
"There are still a lot of things I need to improve. My short game is good but still needs to be better. My driver probably needs to be longer. Everything needs to improve."
Guan hit six birdies and 18 bogeys on his way to a 300 total.