The incumbent Kuomintang (KMT) chairwoman Hung Hsiu-chu stepped down as party chief on Friday.
Hung said she had already decided to leave to ensure a smooth transition, since the party considered her no longer appropriate to stay in the position.
She would no longer run in the future, but would develop younger generation, she said.
Hung was elected as the KMT's first female leader in March 2016, but lost the KMT chairmanship election on May 20 to Wu Den-yih, who won by more than 52 percent of all valid votes.
KMT Vice Chairman Lin Junq-tzer will hold the post of acting chairman from July 1 to Aug. 20, before Wu Den-yih takes office as the party chief.