You can make an application through the Online Application for Taiwan National Park Permits website. From the below link, you can find out the application window dates by using the widget located on the lower right of the web page. For all routes, the application window opens two-month before the intended hiking start date. Applicants can prepare a draft of their application before this date, which is saved on the system for up to 5 full days after the draft was last modified. The system accepts applications daily from 07:00 to 23:00 in the order which they are received: https://npm.nps.gov.tw/

Revisions to the "Notes on Application for Entry into Taroko National Park Ecological Reserve and Existing Use Area (General Controlled Area)" will be implemented starting July 1, 2021. The process for entry applications is modified from the current maximum of 30 days prior to entry and extended to a two-month in advance application. Entry applications for all trails within the Taroko National Park Ecological Protection Area and other Existing Use Area (General Controlled Area) may be applied for two months before entry.

Notice:

A: Qilai (Main/North Peaks, Range from North to South Peak, South Peak, East Ridge); Nanhu (out-and-back to Nanhu Cabin, North Section 1); North Section 1 (Mts. Nanhu and Zhongyangjian), North Section 2 (Y-route, Mt. Shuan/Mt. Lingming, Mt. Shuan Day Ascent); North Sections 1 and 2 traverse; Bilu-Yangtou Traverse; Mt. Qingshui; Other non-traditional routes. The application window opens five days – 2 months before the date of intended entry (closing at 3 pm, five days before the date of planned entry). Applications can be made five days before at 3:00 pm to two months before entering the park, and it is possible to apply for a continuous day trip.

B: Mt. Yangtou Day Ascent, Mt. Bilu Day Ascent: The application window opens three days to 2 months before entry (closing at 3 pm, three days before the date of intended entry). Applications can be made three days before at 3:00 pm to 2 months before entering the park, and it is possible to apply for a continuous day trip.

C: Zhuilu Old Road Day Ascent (out-and-back to 3.1 km): Application window opens one day to two months before entry (closing at 3 pm, one day before the date of intended entry).

D: Zhuilu Old Road Day Ascent (out-and-back to 3.1 km) for Foreign Visitors:

Foreign Visitors may apply up to 4 months ahead
Starting 01 September 2019, foreign visitors are able to submit applications 35 days - 4 months before date of entry via the “Online Application for Taiwan National Park Permits” website. We hope that the new measures will allow more foreign visitors to experience the exquisite scenery within Taroko Gorge. Please contact our Recreation and Services Section (Tel：+886-3-8621576 or +886-3-8621100 ext. 605; Office Hours: Mon – Fri 08:30 – 12:30; 13:30 – 17:30) or review the following details if you wish to apply through this method:

(1): Application window: 35 days to 4 months prior to the date of intended entry (date of intended entry restricted to between Monday – Thursday)
(2): Application Website: Through the English version of the “Online Application for Taiwan National Park Permits” website https://hike.taiwan.gov.tw/en/web_index.aspx
(3): Restrictions: Applicants can submit one application (maximum 12 persons per application) for Zhuilu Old Road per date of intended entry. An applicant can be a team member or a team leader only once per day (e.g. one cannot be a member of a team and the leader of another team on the same day.) All team members must possess foreign nationality; please upload the photo page of your valid passport or a resident ID Card as proof.
(4): Once an application has been approved, the date of entry and the names of all team members (including the leader, team members, and the emergency coordinator) cannot be altered, and additional team members cannot be added to the same application. Cancellation (for an individual or for the entire party, excluding the team leader) can be accepted. Separate applications should be submitted if additional members wish to hike on the same date of intended entry.
(5): Standby Measure: There will be no standby measures (i.e. waitlist) for foreign visitor applications to Zhuilu Old Road. All applicants regardless of nationality are welcome to apply through the standard application window (1 – 30 days before date of intended entry) if the quota for foreign visitors has already been reached.

E: All application cases are filed by the time of online application. Please refer to the latest revision of the "Important Notices on Application for Entry into the Park Ecological Protection Areas and Other Existing Use Area (General Controlled Area) " for more information.