The 27-year-old replaced Iraqi Younes Mahmoud in the Qatari team.
"I am happy to sign with a big club like Al Gharafa," said the playmaker.
"I had many offers but I chose Al Gharafa to help them in the coming local and Asian challenges.
"My main target is to get titles with Al Gharafa. It doesn't matter who scores the goals as we want to win the titles.
"The Qatari League is among the best leagues in Persian Gulf," Khalatbari said.