Where is the highest airstip in the world?

La Paz Bolivia

Here is another answer: Bangda, China (elevation 4334 m). It is located between Chengdu and Lhasa.

http://www.boeing.com/news/releases/1995/news.release.950501.html
Ladakh, Pakistan is "only" at 3256 m, and Lhasa, Tibet (where I was earlier last year) is at 3650 m. They all have commercial airports. La Paz, Bolivia has an airport at 4040 m elevation.

The highest airstrip in the world is the Daocheng Yading Airport, located in the Garzi Tibetan Autonomous Prefecture, Sichuan Province, China. It stands at an elevation of approximately 4,411 meters (14,472 feet) above sea level. To find out this information, one can utilize various sources such as search engines or online encyclopedias. A simple search with the query "highest airstrip in the world" will provide you with the required information. Additionally, aviation websites or travel guides might also provide details about the highest airstrip in the world.