Lakers spokesman John Black declined Saturday to discuss details of the terms and said it could be some time before a contract is signed.
"It could be weeks, it could be days," he said.
The 6-foot-9, 212-pound Sun was the Lakers' second-round draft pick last year. He played with the Aoshen club in Beijing and with the Chinese national team before the Olympics.
Sun has played mostly point guard in China but Black wouldn't specify his role with the Lakers, saying it was a coaching decision. Derek Fisher and Jordan Farmar were the top two point guards when the Lakers lost to Boston in the NBA finals.
The Lakers are considering moving Bryant to small forward and making frontcourt player Lamar Odom a guard.