The Cameroonian midfielder has been in talks with the Catalan giants over the past week.
Now, it seems that the move has grown even closer after the Gunners revealed that both clubs have agreed terms.
"Arsenal Football Club can confirm that terms have been agreed for the transfer of Alex Song to Barcelona," read a statement on Arsenal's official website.
"Song will now travel to the Catalan club to agree personal terms and undergo a medical ahead of the proposed move."
Song joined Arsene Wenger's side in 2006 from French side Bastia.