Bass dulu (pinyin: dī yīn dū lū), alias cluster, big dongxiao, is a musical instrument of Li nationality, popular in Hainan Province.

The bass dulu has a shape that resembles a western musical instrument bass oboe. It is made of bamboo. The length of the tube is 100 cm to 130 cm and the diameter of the tube is 3 cm. There is a bamboo hat, and a small bamboo pipe 20 cm long is attached to the hat as a blowpipe.

In Li's house, you can sometimes see the bass toot with a longer body, and the bottom sound hole needs to be pressed with your toes.