Approximately 400 species of butterflies have been found in Taiwan, which is known in the international community as the 'Butterfly Kingdom'. As many as 180 species of butterflies have been recorded within Yangmingshan National Park. Every year from May to July, a large number of butterflies choose this time of year to emerge from their cocoons because of the warmer weather and the flowering of many nectar plants, such as the Eupatorium shimadai, Angelica dahurica and Sambucus chinensis. Within the park there are many scenes of Milkweed butterflies fluttering among Eupatorium shimadai on top of hills and mountains covered with arrow bamboo and silver grass, among which Mt. Datun—which is the largest and easiest to access—boasts world-class scenery.

The Mt. Datun car lane is one of the park's important butterfly-viewing routes. In order to preserve the habitat's air quality and provide a safe butterfly-viewing environment for visitors, the car lane is off-limits to all vehicles from May 26 to June 24, every day from 8 AM to 4 PM. Excluded vehicles include bicycles but excludes official park vehicles. The park headquarters apologizes in advance for the inconvenience.

The park headquarters advises visitors to make use of public transportation to enjoy butterfly-viewing with a healthy and relaxed attitude. For those guest who need to drive their own vehicles, the park suggests parking in a parking lot nearby an MRT station and taking bus 260, R5, or Royal Bus 1717 from MRT Jiantan Station, bus 230 or S9 from MRT Beitou Station, or bus S8 from MRT Shipai Station to the Yangmingshan stop or the Yangmingshan Bus Terminal. From there, visitors can transfer to shuttle bus 108 to Erziping stop.

Due to the easily changing weather conditions and lower temperatures in the mountains （around 3 to 5 degrees lower than in the city）, the park advises visitors to bring along rain gear, warm clothing, and any personal medication. To comply with our "Leave No Trace" policy, please do not litter, pick flowers, or touch or disturb animals such as the butterflies. Again, the park reminds all visitors to take their trash down the mountain and dispose of it properly in trash bins.