The 32-year-old has struggled since signing from Manchester United in a £2m deal last summer and is ready to call an end to his career even if QPR avoid relegation from the Premier League.
The South Korean, who signed a two-year contract at Loftus Road, has failed to find the fitness and form that saw him win a Champions League medal and four Premier League titles at Old Trafford.
His father Sung-jong Park said: "Nobody knows the future; maybe he could play one more year with a new team after next season. But I think [Ji-Sung] has made his mind up to retire. He thinks he's played enough.
"He's never had times like this with PSV Eindhoven or Manchester United. My son has had difficult times at QPR this season; it was a new experience to him.
"Ji-sung said it's difficult to keep his feel for the game as his playing time is inconsistent, but he doesn't have any hard feelings."