Griffiths, who has played 55 games for Newcastle, had been contracted until the end of the 2013/14 domestic A-League season.
"While our preference was for Ryan to stay, we understand at 32 years of age, going over to China now secures his family financially," coach Gary van Egmond said.
Griffiths said it was a hard decision because he loved Newcastle.
"But I needed to consider my young family and do what is best for them, and right now that is going to play in China," he said.
Older brother Joel recently returned to the A-League to link up with Sydney FC after several seasons in China including at Beijing Guoan.