Jiuzhaigou is a nature reserve and national park located in the north of Sichuan Province in southwestern China. The southern end is the Minshan Garna Peak, and the northern end is the Huanglong Scenic Area. It originates from the Baishui River area, one of the headwaters of the Jialing River and a part of the Yangtze River system.

The Jiuzhaigou valley it's known for its many multi-level waterfalls, colorful lakes, and snow-capped peaks and diverse forest ecosystems. With and area of over 720 km², it's part of the Min Mountains on the edge of the Tibetan Plateau and has an altitude of over 4800 meters. Its elevation ranges from 2,000 to 4,500 meters (6,600 to 14,800 ft).

The Five-Flower Lake is one of the most famous lakes in Jiuzhaigou (see thumbnail). Its captivating colors are due to the concentration of minerals and other deposits. The water is crystal clear, and it is possible to see the trunks resting at the bottom of the lake. Despite being visited by thousands of tourists every year, its clarity has not diminished.

Jiuzhaigou (literally "Nine Settlement Valley") takes its name from the nine Tibetan settlements along its length.

Jiuzhaigou was inscribed by UNESCO as a World Heritage Site in 1992 and a World Biosphere Reserve in 1997. It belongs in the category V (Protected Landscape) in the IUCN system of protected area categorization.