The Facebook page of Taiwan's new president-elect Tsai Ing-wen has been flooded with hostile posts, seemingly from mainland China.
Tens of thousands of posts demanded that the island be reunified with the mainland, under Beijing's control.
Meanwhile, China conducted military drills on its coast opposite Taiwan.
Ms Tsai and her Democratic Progressive Party (DPP) won a landslide victory in presidential and parliamentary elections on Saturday.
The DPP is broadly supportive of independence from China.
Beijing considers Taiwan a breakaway province that must one day be brought back under mainland control.
It is concerned that Taiwan may declare formal independence although Ms Tsai has not declared herself in favour of such a move.
'Love the motherland'
Ms Tsai brushed off the Facebook campaign on Thursday, saying: "The greatness of this country lies in how every single person can exercise their rights."
Her party, too, said they "respected" those who exercised freedom of speech.