The quake hit at 5:55 am (local time) and was centred 81 kilometres east of the city of Hualian at a depth of 10 kilometres, USGS said.
The tremor comes after a 6.4-magnitude earthquake in February left 117 dead when an apartment complex collapsed in the southern city of Tainan.
That quake also raised questions over shoddy construction — five people have been charged over the deadly building collapse.
Taiwan lies near the junction of two tectonic plates and is regularly hit by earthquakes.
A 6.3-magnitude quake that hit central Taiwan in June 2013 killed four people and caused widespread landslides.
The island’s worst quake disaster came in September 1999 when a 7.6-magnitude earthquake killed around 2,400 people.
PTI