One of the premier strikers in China, Li Jinyu earned his reputation early when he was the stars of the Chinese youth team that studied in Brazil for a training programme sponsored by Shenzhen Jianlibao. This then saw him called up to the Chinese under-20 national team and gave him a chance to play in the 1997 FIFA World Youth Championship which attracted the interests of French side AS Nancy who acquired him on loan for one season. Li's time at AS Nancy was not successful and he would return to China to sign with Liaoning Whowin, immediately showing his potential that was missing at AS Nancy when he became an integral member of the team that narrowly lost out on the league title in 1999. While he would personally win his first Golden Boot award in 2002, he did not win any trophies with his club Liaoning during his time with them.
At the beginning of the 2004 league season, Shandong Luneng were willing to pay 4,900,000 yuan to make him the most expensive signing in Chinese football transfer history at the time. He would immediately become an integral member of the team and would repay them by helping them win the Chinese FA Cup and Chinese Super League Cup at the end of the season. The 2006 league season would see him reach his peak when he won the league title, the Chinese FA Cup, and the Golden Boot award with the team. The 2007 league season would see him officially become the most prolific player within the league when he broke Hao Haidong's goal record, however he could not aid Shandong to another league title. Despite his tradition in scoring, his prolific goalscoring dropped during the 2008 league season when he only scored six goals, nevertheless he was still able to win another league title. By the 2010 league season, Li would become a fringe player within the team, however he would still go on to win the league title once more and decided to retire at the end of the season.