Taiwan Tuesday warned that approaching Typhoon Saola was likely to bring heavy rains and trigger landslides on the island after it killed eight people in the Philippines.
The Central Weather Bureau also asked the public to stay away from the low-lying areas prone to flooding as thousands of fishing boats returned to port to seek shelter.
The defence ministry ordered more than 46,000 soldiers to stand by.
As of 1230 GMT, Saola was 330 kilometres (205 miles) east of Eruanpi, the southernmost tip of the island.
With a radius of 220 kilometres and packing winds gusting at up to 119 kilometres a hour, the typhoon was moving north-northwest at nine kilometres per hour.
The storm pounded the Philippines Monday, leaving millions of people without power and forcing the authorities to evacuate more than 145,000 people.