Li, ranked third in the world and the tournament defending champion, topped eighth-seeded Annika Beck 6-1, 6-3 in her semifinal Friday. Peng, the No. 5-seed ranked No. 42, advanced when Vania King was unable to play due to a right leg injury.
Li's win over Beck lasted only 61 minutes. Li was 0-for-2 in saving break points but cashed in six of her own seven break opportunities. She won 64 percent of the points on serve and 63 percent off Beck's.
Li has beaten Peng five of their six previous meetings, including a 6-4, 6-0 decision in last year's Shenzhen semifinals. Peng, who is 0-5 in previous WTA finals, last defeated Li in 2011 in a three-set decision. Li is 7-11 in title matches and was 1-4 in finals in 2013.