Dulu (pinyin: dū lū), alias cluster, dongxiao, is a musical instrument of Li nationality, which is popular in Qiongzhong, Baoting, Ledong, Changjiang and Haikou in Hainan Province.

The Dulu tube body is made of thin bamboo tubes with bamboo knots on the upper end. The tube length is 90 cm and the diameter is 1.8 cm to 2 cm.

Dulu is a common musical instrument used by young Li people to express and convey love. On the slack nights of farming, when the Li family was born in a dormitory (a single house for unmarried young men and women of the Li nationality) or on the lawn, when they whistle to express their thoughts for the girl, the girls often use the nose flute to answer.

Dulu is mostly used for solo, instrumental ensemble or singing and dancing accompaniment. The music is mostly folk tunes, such as "Want to Miss You" and so on.