Zheng returned to Shandong Luneng at the end of the 2006–07 season under the terms of his loan deal. He played once more for the club in a 6–1 loss against Beijing Guoan before he returned to Charlton on a permanent deal in August 2007. He joined for a fee of £2 million and signed a two-year contract with the club. He scored a total of seven league goals in the 2007–08 season; however, he was less effective in the second half of the season as a result of fatigue.