Jung Jae-sung
In July, after a period of disappointing results in men's doubles, Lee became runner-up with Jung at the Thailand Open, losing to Hwang Ji-man and Lee Jae-jin. Not much later, the pair went on to take the silver medal in the 2007 BWF World Championships. They were defeated in the final by Markis Kido and Hendra Setiawan of Indonesia, 19–21, 19–21. In mixed doubles, Lee reached the third round with Lee Hyo-jung. There they lost to Nathan Robertson and Gail Emms of England in three games. With Jung Jae-sung, the rest of the year also resulted in quite disappointing achievements, as he failed to pass the quarterfinals in any major events, except in the French Open. Lee and Jung there lost to the eventual winners, Cai Yun and Fu Haifeng of China.