Born in Nanjing, Yafan Wang began playing tennis when she was nine. She made her professional debut at ITF level in Quanzhou in 2009 and contested WTA qualifying for the first time at 2012 Beijing.
Her WTA singles main draw debut came at 2014 Guangzhou, where she upset Samantha Stosur in round one, registering her maiden Top 20 win, and qualifiers Martic and Kailin en route to the semifinals (l. eventual champion Niculescu).
In 2015 won two WTA doubles titles in Kuala Lumpur and Zhuhai and a WTA 125k Title in Hua Hin (all w/Liang).
In 2016 she made her Fed Cup debut for China and cracked Top 50 in doubles, reaching No.49 on February 15. In singles, her best result on ITF Circuit was the runner-up finish in Kashiwa in April. At WTA level, she reached the second-round at US Open, on her main draw debut at the tournament (as qualifier, b.Sakkari in her first major main draw win, l.Tsurenko). She also made second-round appearances in Beijing (l. Kvitova) and Tianjin (l. Han).
In 2017 after posting her career-high ranking of No.113 on January 9, she missed the first half of the season due to illness. She marked her comeback with a series of opening round defeats on ITF Circuit before lifting the eighth and ninth career title at this level at $25k event in Tianjin and $60k tournament in Liuzhou. At WTA level, the season highlight was reaching the second semifinal in Nanchang (l.Hibino). She ended 2017 ranked No.168 (down from career-best finish of No.115 in 2016).