Chime bells, or bianzhong, are a kind of percussion musical instrument made of bronze.

Chime bells were divided into groups according to their size, temperament, pitch and were hung on a rack. A small hammer or wooden club is used to hit the bell to make a resonant and agreeable sound.

Chime bells of Yi, are the largest and the most complete set of ancient chimes existing today in China. They were unearthed from the tomb of Yi, Marquis of Zeng, a small state of the Warring States Period (475 BC - 221 BC), in 1978. When they were found, all bells were still hanging on rack.

There are 64 bells altogether, hung in eight groups on wooden or bronze bars. The rack, 10.79 m long, 2.67 m high, is made of three bars, namely, the upper, middle and lower bars, held up by six bronze warriors and a few round wooden posts. The 64 bells weigh 2,500 kg. The largest bell exceed 1.5 m in height and weight more than 200 kg. It is extremely rare to see a set with so many bells of such weight and size.

Chime bells of Yi are exquisitely cast and look very elegant. To help artists to perform music, there are intructions on each bell with 2,828 characters in all. There are also words about the hanging indication and musical temperament that are called the "valuable music theory work". Chime bells of Yi shows that, as early as the Warring States Period, China already had a very rich musical culture. Chime bells still could produce a pure and accurate note after unearthed. The tone is execellent and the timbre is pure.

After excavation of music, Chinese musicians created a melody entitled Bianzhong Yuewu - music and dance accompanied by chime bells, to once again demonstrate the charm of ancient Chinese music.